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polardbxengine/storage/innobase/row/row0sel.cc

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/*****************************************************************************
Copyright (c) 1997, 2019, Oracle and/or its affiliates. All Rights Reserved.
Copyright (c) 2008, Google Inc.
Portions of this file contain modifications contributed and copyrighted by
Google, Inc. Those modifications are gratefully acknowledged and are described
briefly in the InnoDB documentation. The contributions by Google are
incorporated with their permission, and subject to the conditions contained in
the file COPYING.Google.
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License, version 2.0, as published by the
Free Software Foundation.
This program is also distributed with certain software (including but not
limited to OpenSSL) that is licensed under separate terms, as designated in a
particular file or component or in included license documentation. The authors
of MySQL hereby grant you an additional permission to link the program and
your derivative works with the separately licensed software that they have
included with MySQL.
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License, version 2.0,
for more details.
You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*****************************************************************************/
/** @file row/row0sel.cc
Select
Created 12/19/1997 Heikki Tuuri
*******************************************************/
#include "row0sel.h"
#include <sys/types.h>
#include "btr0btr.h"
#include "btr0cur.h"
#include "btr0sample.h"
#include "btr0sea.h"
#include "buf0lru.h"
#include "dict0boot.h"
#include "dict0dd.h"
#include "dict0dict.h"
#include "eval0eval.h"
#include "gis0rtree.h"
#include "ha_innodb.h"
#include "ha_prototypes.h"
#include "handler.h"
#include "lob0lob.h"
#include "lob0undo.h"
#include "lock0lock.h"
#include "mach0data.h"
#include "pars0pars.h"
#include "pars0sym.h"
#include "que0que.h"
#include "read0read.h"
#include "record_buffer.h"
#include "rem0cmp.h"
#include "row0mysql.h"
#include "row0row.h"
#include "row0upd.h"
#include "row0vers.h"
#include "srv0mon.h"
#include "trx0trx.h"
#include "trx0undo.h"
#include "ut0new.h"
#include "my_dbug.h"
#include "lizard0dict.h"
#include "lizard0cleanout.h"
#include "lizard0undo.h"
#include "lizard0gp.h"
/** Maximum number of rows to prefetch; MySQL interface has another parameter */
#define SEL_MAX_N_PREFETCH 16
/** Number of rows fetched, after which to start prefetching; MySQL interface
has another parameter */
#define SEL_PREFETCH_LIMIT 1
/** When a select has accessed about this many pages, it returns control back
to que_run_threads: this is to allow canceling runaway queries */
#define SEL_COST_LIMIT 100
/** Flags for search shortcut */
#define SEL_FOUND 0
#define SEL_EXHAUSTED 1
#define SEL_RETRY 2
/** Returns TRUE if the user-defined column in a secondary index record
is alphabetically the same as the corresponding BLOB column in the clustered
index record.
NOTE: the comparison is NOT done as a binary comparison, but character
fields are compared with collation!
@return true if the columns are equal */
static ibool row_sel_sec_rec_is_for_blob(
trx_t *trx, /*!< in: the operating transaction */
ulint mtype, /*!< in: main type */
ulint prtype, /*!< in: precise type */
ulint mbminmaxlen, /*!< in: minimum and maximum length of
a multi-byte character */
const byte *clust_field, /*!< in: the locally stored part of
the clustered index column, including
the BLOB pointer; the clustered
index record must be covered by
a lock or a page latch to protect it
against deletion (rollback or purge) */
ulint clust_len, /*!< in: length of clust_field */
const byte *sec_field, /*!< in: column in secondary index */
ulint sec_len, /*!< in: length of sec_field */
ulint prefix_len, /*!< in: index column prefix length
in bytes */
dict_table_t *table) /*!< in: table */
{
ulint len;
byte buf[REC_VERSION_56_MAX_INDEX_COL_LEN];
/* This function should never be invoked on tables in
ROW_FORMAT=REDUNDANT or ROW_FORMAT=COMPACT, because they
should always contain enough prefix in the clustered index record. */
ut_ad(dict_table_has_atomic_blobs(table));
ut_a(clust_len >= BTR_EXTERN_FIELD_REF_SIZE);
ut_ad(prefix_len >= sec_len);
ut_ad(prefix_len > 0);
ut_a(prefix_len <= sizeof buf);
if (!memcmp(clust_field + clust_len - BTR_EXTERN_FIELD_REF_SIZE,
field_ref_zero, BTR_EXTERN_FIELD_REF_SIZE)) {
/* The externally stored field was not written yet.
This record should only be seen by
trx_rollback_or_clean_all_recovered() or any
TRX_ISO_READ_UNCOMMITTED transactions. */
return (FALSE);
}
len = lob::btr_copy_externally_stored_field_prefix(
trx, table->first_index(), buf, prefix_len,
dict_tf_get_page_size(table->flags), clust_field,
dict_table_is_sdi(table->id), clust_len);
if (len == 0) {
/* The BLOB was being deleted as the server crashed.
There should not be any secondary index records
referring to this clustered index record, because
btr_free_externally_stored_field() is called after all
secondary index entries of the row have been purged. */
return (FALSE);
}
len = dtype_get_at_most_n_mbchars(prtype, mbminmaxlen, prefix_len, len,
(const char *)buf);
/* We are testing for equality; ASC/DESC does not matter. */
return (!cmp_data_data(mtype, prtype, true, buf, len, sec_field, sec_len));
}
/** Returns TRUE if the user-defined column values in a secondary index record
are alphabetically the same as the corresponding columns in the clustered
index record.
NOTE: the comparison is NOT done as a binary comparison, but character
fields are compared with collation!
@param[in] sec_rec secondary index record
@param[in] sec_index secondary index
@param[in] clust_rec clustered index record;
must be protected by a page s-latch
@param[in] clust_index clustered index
@param[in] thr query thread
@param[out] is_equal set to true if the secondary record is equal
to the corresponding fields in the clustered record, when compared with
collation; false if not equal or if the
clustered record has been marked for deletion; only valid if DB_SUCCESS was
returned
@return DB_SUCCESS or error code */
static dberr_t row_sel_sec_rec_is_for_clust_rec(
const rec_t *sec_rec, dict_index_t *sec_index, const rec_t *clust_rec,
dict_index_t *clust_index, que_thr_t *thr, bool &is_equal) {
const byte *sec_field;
ulint sec_len;
const byte *clust_field;
ulint n;
ulint i;
mem_heap_t *heap = NULL;
ulint clust_offsets_[REC_OFFS_NORMAL_SIZE];
ulint sec_offsets_[REC_OFFS_SMALL_SIZE];
ulint *clust_offs = clust_offsets_;
ulint *sec_offs = sec_offsets_;
trx_t *trx = thr_get_trx(thr);
dberr_t err = DB_SUCCESS;
is_equal = true;
rec_offs_init(clust_offsets_);
rec_offs_init(sec_offsets_);
if (rec_get_deleted_flag(clust_rec, dict_table_is_comp(clust_index->table))) {
/* The clustered index record is delete-marked;
it is not visible in the read view. Besides,
if there are any externally stored columns,
some of them may have already been purged. */
is_equal = false;
return (DB_SUCCESS);
}
heap = mem_heap_create(256);
clust_offs = rec_get_offsets(clust_rec, clust_index, clust_offs,
ULINT_UNDEFINED, &heap);
sec_offs =
rec_get_offsets(sec_rec, sec_index, sec_offs, ULINT_UNDEFINED, &heap);
n = dict_index_get_n_ordering_defined_by_user(sec_index);
for (i = 0; i < n; i++) {
const dict_field_t *ifield;
const dict_col_t *col;
ulint clust_pos = 0;
ulint clust_len;
ulint len;
row_ext_t *ext;
ifield = sec_index->get_field(i);
col = ifield->col;
/* For virtual column, its value will need to be
reconstructed from base column in cluster index */
if (col->is_virtual()) {
const dict_v_col_t *v_col;
const dtuple_t *row;
dfield_t *vfield;
v_col = reinterpret_cast<const dict_v_col_t *>(col);
row = row_build(ROW_COPY_POINTERS, clust_index, clust_rec, clust_offs,
NULL, NULL, NULL, &ext, heap);
vfield = innobase_get_computed_value(row, v_col, clust_index, &heap, heap,
NULL, thr_get_trx(thr)->mysql_thd,
thr->prebuilt->m_mysql_table, NULL,
NULL, NULL);
if (vfield == NULL) {
/* This may happen e.g. when this statement is executed in
* read-uncommited isolation and value (like json function)
* depends on an externally stored lob (like json) which
* was not written yet. */
err = DB_COMPUTE_VALUE_FAILED;
goto func_exit;
}
clust_len = vfield->len;
clust_field = static_cast<byte *>(vfield->data);
} else {
clust_pos = dict_col_get_clust_pos(col, clust_index);
clust_field = rec_get_nth_field_instant(clust_rec, clust_offs, clust_pos,
clust_index, &clust_len);
}
sec_field = rec_get_nth_field(sec_rec, sec_offs, i, &sec_len);
len = clust_len;
if (ifield->prefix_len > 0 && len != UNIV_SQL_NULL &&
sec_len != UNIV_SQL_NULL && !col->is_virtual()) {
if (rec_offs_nth_extern(clust_offs, clust_pos)) {
len -= BTR_EXTERN_FIELD_REF_SIZE;
}
len = dtype_get_at_most_n_mbchars(col->prtype, col->mbminmaxlen,
ifield->prefix_len, len,
(char *)clust_field);
/* Check sec index field matches that of cluster index
in the case of for table with ATOMIC BLOB, note
we also need to check if sec_len is 0 */
if (rec_offs_nth_extern(clust_offs, clust_pos) &&
(len < sec_len ||
(dict_table_has_atomic_blobs(sec_index->table) && sec_len == 0))) {
if (!row_sel_sec_rec_is_for_blob(
trx, col->mtype, col->prtype, col->mbminmaxlen, clust_field,
clust_len, sec_field, sec_len, ifield->prefix_len,
clust_index->table)) {
is_equal = false;
goto func_exit;
}
continue;
}
}
/* For spatial index, the first field is MBR, we check
if the MBR is equal or not. */
if (dict_index_is_spatial(sec_index) && i == 0) {
rtr_mbr_t tmp_mbr;
rtr_mbr_t sec_mbr;
byte *dptr = const_cast<byte *>(clust_field);
ut_ad(clust_len != UNIV_SQL_NULL);
/* For externally stored field, we need to get full
geo data to generate the MBR for comparing. */
if (rec_offs_nth_extern(clust_offs, clust_pos)) {
dptr = lob::btr_copy_externally_stored_field(
trx, clust_index, &clust_len, nullptr, dptr,
dict_tf_get_page_size(sec_index->table->flags), len,
dict_index_is_sdi(sec_index), heap);
}
get_mbr_from_store(sec_index->rtr_srs.get(), dptr,
static_cast<uint>(clust_len), SPDIMS,
reinterpret_cast<double *>(&tmp_mbr), nullptr);
rtr_read_mbr(sec_field, &sec_mbr);
if (!mbr_equal_cmp(sec_index->rtr_srs.get(), &sec_mbr, &tmp_mbr)) {
is_equal = false;
goto func_exit;
}
} else if (col->is_multi_value()) {
if (!is_multi_value_clust_and_sec_equal(clust_field, clust_len, sec_field,
sec_len, col)) {
is_equal = false;
goto func_exit;
}
} else {
/* We are testing for equality; ASC/DESC does not
matter */
if (0 != cmp_data_data(col->mtype, col->prtype, true, clust_field, len,
sec_field, sec_len)) {
is_equal = false;
goto func_exit;
}
}
}
func_exit:
if (UNIV_LIKELY_NULL(heap)) {
mem_heap_free(heap);
}
return (err);
}
/** Creates a select node struct.
@return own: select node struct */
sel_node_t *sel_node_create(
mem_heap_t *heap) /*!< in: memory heap where created */
{
sel_node_t *node;
node = static_cast<sel_node_t *>(mem_heap_alloc(heap, sizeof(sel_node_t)));
node->common.type = QUE_NODE_SELECT;
node->state = SEL_NODE_OPEN;
node->plans = NULL;
return (node);
}
/** Frees the memory private to a select node when a query graph is freed,
does not free the heap where the node was originally created. */
void sel_node_free_private(sel_node_t *node) /*!< in: select node struct */
{
ulint i;
plan_t *plan;
if (node->plans != NULL) {
for (i = 0; i < node->n_tables; i++) {
plan = sel_node_get_nth_plan(node, i);
btr_pcur_close(&(plan->pcur));
btr_pcur_close(&(plan->clust_pcur));
if (plan->old_vers_heap) {
mem_heap_free(plan->old_vers_heap);
}
}
}
}
/** Evaluates the values in a select list. If there are aggregate functions,
their argument value is added to the aggregate total. */
UNIV_INLINE
void sel_eval_select_list(sel_node_t *node) /*!< in: select node */
{
que_node_t *exp;
exp = node->select_list;
while (exp) {
eval_exp(exp);
exp = que_node_get_next(exp);
}
}
/** Assigns the values in the select list to the possible into-variables in
SELECT ... INTO ... */
UNIV_INLINE
void sel_assign_into_var_values(sym_node_t *var, /*!< in: first variable in a
list of variables */
sel_node_t *node) /*!< in: select node */
{
que_node_t *exp;
if (var == NULL) {
return;
}
for (exp = node->select_list; var != 0;
var = static_cast<sym_node_t *>(que_node_get_next(var))) {
ut_ad(exp);
eval_node_copy_val(var->alias, exp);
exp = que_node_get_next(exp);
}
}
/** Resets the aggregate value totals in the select list of an aggregate type
query. */
UNIV_INLINE
void sel_reset_aggregate_vals(sel_node_t *node) /*!< in: select node */
{
func_node_t *func_node;
ut_ad(node->is_aggregate);
for (func_node = static_cast<func_node_t *>(node->select_list);
func_node != 0;
func_node = static_cast<func_node_t *>(que_node_get_next(func_node))) {
eval_node_set_int_val(func_node, 0);
}
node->aggregate_already_fetched = FALSE;
}
/** Copies the input variable values when an explicit cursor is opened. */
UNIV_INLINE
void row_sel_copy_input_variable_vals(sel_node_t *node) /*!< in: select node */
{
sym_node_t *var;
var = UT_LIST_GET_FIRST(node->copy_variables);
while (var) {
eval_node_copy_val(var, var->alias);
var->indirection = NULL;
var = UT_LIST_GET_NEXT(col_var_list, var);
}
}
/** Fetches the column values from a record. */
static void row_sel_fetch_columns(
trx_t *trx, /*!< in: the current transaction or nullptr */
dict_index_t *index, /*!< in: record index */
const rec_t *rec, /*!< in: record in a clustered or non-clustered
index; must be protected by a page latch */
const ulint *offsets, /*!< in: rec_get_offsets(rec, index) */
sym_node_t *column) /*!< in: first column in a column list, or
NULL */
{
dfield_t *val;
ulint index_type;
ulint field_no;
const byte *data;
ulint len;
ut_ad(rec_offs_validate(rec, index, offsets));
if (index->is_clustered()) {
index_type = SYM_CLUST_FIELD_NO;
} else {
index_type = SYM_SEC_FIELD_NO;
}
while (column) {
mem_heap_t *heap = NULL;
ibool needs_copy;
field_no = column->field_nos[index_type];
if (field_no != ULINT_UNDEFINED) {
if (UNIV_UNLIKELY(rec_offs_nth_extern(offsets, field_no))) {
/* Copy an externally stored field to the
temporary heap, if possible. */
heap = mem_heap_create(1);
data = lob::btr_rec_copy_externally_stored_field(
trx, index, rec, offsets, dict_table_page_size(index->table),
field_no, &len, nullptr, dict_index_is_sdi(index), heap);
/* data == NULL means that the
externally stored field was not
written yet. This record
should only be seen by
trx_rollback_or_clean_all_recovered() or any
TRX_ISO_READ_UNCOMMITTED
transactions. The InnoDB SQL parser
(the sole caller of this function)
does not implement READ UNCOMMITTED,
and it is not involved during rollback. */
ut_a(data);
ut_a(len != UNIV_SQL_NULL);
needs_copy = TRUE;
} else {
data = rec_get_nth_field_instant(rec, offsets, field_no, index, &len);
needs_copy = column->copy_val;
}
if (needs_copy) {
eval_node_copy_and_alloc_val(column, data, len);
} else {
val = que_node_get_val(column);
dfield_set_data(val, data, len);
}
if (UNIV_LIKELY_NULL(heap)) {
mem_heap_free(heap);
}
}
column = UT_LIST_GET_NEXT(col_var_list, column);
}
}
/** Allocates a prefetch buffer for a column when prefetch is first time done.
*/
static void sel_col_prefetch_buf_alloc(
sym_node_t *column) /*!< in: symbol table node for a column */
{
sel_buf_t *sel_buf;
ulint i;
ut_ad(que_node_get_type(column) == QUE_NODE_SYMBOL);
column->prefetch_buf = static_cast<sel_buf_t *>(
ut_malloc_nokey(SEL_MAX_N_PREFETCH * sizeof(sel_buf_t)));
for (i = 0; i < SEL_MAX_N_PREFETCH; i++) {
sel_buf = column->prefetch_buf + i;
sel_buf->data = NULL;
sel_buf->len = 0;
sel_buf->val_buf_size = 0;
}
}
/** Frees a prefetch buffer for a column, including the dynamically allocated
memory for data stored there. */
void sel_col_prefetch_buf_free(
sel_buf_t *prefetch_buf) /*!< in, own: prefetch buffer */
{
sel_buf_t *sel_buf;
ulint i;
for (i = 0; i < SEL_MAX_N_PREFETCH; i++) {
sel_buf = prefetch_buf + i;
if (sel_buf->val_buf_size > 0) {
ut_free(sel_buf->data);
}
}
ut_free(prefetch_buf);
}
/** Pops the column values for a prefetched, cached row from the column prefetch
buffers and places them to the val fields in the column nodes. */
static void sel_dequeue_prefetched_row(
plan_t *plan) /*!< in: plan node for a table */
{
sym_node_t *column;
sel_buf_t *sel_buf;
dfield_t *val;
byte *data;
ulint len;
ulint val_buf_size;
ut_ad(plan->n_rows_prefetched > 0);
column = UT_LIST_GET_FIRST(plan->columns);
while (column) {
val = que_node_get_val(column);
if (!column->copy_val) {
/* We did not really push any value for the
column */
ut_ad(!column->prefetch_buf);
ut_ad(que_node_get_val_buf_size(column) == 0);
ut_d(dfield_set_null(val));
goto next_col;
}
ut_ad(column->prefetch_buf);
ut_ad(!dfield_is_ext(val));
sel_buf = column->prefetch_buf + plan->first_prefetched;
data = sel_buf->data;
len = sel_buf->len;
val_buf_size = sel_buf->val_buf_size;
/* We must keep track of the allocated memory for
column values to be able to free it later: therefore
we swap the values for sel_buf and val */
sel_buf->data = static_cast<byte *>(dfield_get_data(val));
sel_buf->len = dfield_get_len(val);
sel_buf->val_buf_size = que_node_get_val_buf_size(column);
dfield_set_data(val, data, len);
que_node_set_val_buf_size(column, val_buf_size);
next_col:
column = UT_LIST_GET_NEXT(col_var_list, column);
}
plan->n_rows_prefetched--;
plan->first_prefetched++;
}
/** Pushes the column values for a prefetched, cached row to the column prefetch
buffers from the val fields in the column nodes. */
UNIV_INLINE
void sel_enqueue_prefetched_row(plan_t *plan) /*!< in: plan node for a table */
{
sym_node_t *column;
sel_buf_t *sel_buf;
dfield_t *val;
byte *data;
ulint len;
ulint pos;
ulint val_buf_size;
if (plan->n_rows_prefetched == 0) {
pos = 0;
plan->first_prefetched = 0;
} else {
pos = plan->n_rows_prefetched;
/* We have the convention that pushing new rows starts only
after the prefetch stack has been emptied: */
ut_ad(plan->first_prefetched == 0);
}
plan->n_rows_prefetched++;
ut_ad(pos < SEL_MAX_N_PREFETCH);
for (column = UT_LIST_GET_FIRST(plan->columns); column != 0;
column = UT_LIST_GET_NEXT(col_var_list, column)) {
if (!column->copy_val) {
/* There is no sense to push pointers to database
page fields when we do not keep latch on the page! */
continue;
}
if (!column->prefetch_buf) {
/* Allocate a new prefetch buffer */
sel_col_prefetch_buf_alloc(column);
}
sel_buf = column->prefetch_buf + pos;
val = que_node_get_val(column);
data = static_cast<byte *>(dfield_get_data(val));
len = dfield_get_len(val);
val_buf_size = que_node_get_val_buf_size(column);
/* We must keep track of the allocated memory for
column values to be able to free it later: therefore
we swap the values for sel_buf and val */
dfield_set_data(val, sel_buf->data, sel_buf->len);
que_node_set_val_buf_size(column, sel_buf->val_buf_size);
sel_buf->data = data;
sel_buf->len = len;
sel_buf->val_buf_size = val_buf_size;
}
}
/** Builds a previous version of a clustered index record for a consistent read
@return DB_SUCCESS or error code */
static MY_ATTRIBUTE((warn_unused_result)) dberr_t row_sel_build_prev_vers(
lizard::Vision *vision, /*!< in: read view */
dict_index_t *index, /*!< in: plan node for table */
rec_t *rec, /*!< in: record in a clustered index */
ulint **offsets, /*!< in/out: offsets returned by
rec_get_offsets(rec, plan->index) */
mem_heap_t **offset_heap, /*!< in/out: memory heap from which
the offsets are allocated */
mem_heap_t **old_vers_heap, /*!< out: old version heap to use */
rec_t **old_vers, /*!< out: old version, or NULL if the
record does not exist in the view:
i.e., it was freshly inserted
afterwards */
mtr_t *mtr) /*!< in: mtr */
{
dberr_t err;
if (*old_vers_heap) {
mem_heap_empty(*old_vers_heap);
} else {
*old_vers_heap = mem_heap_create(512);
}
err = row_vers_build_for_consistent_read(rec, mtr, index, offsets, vision,
offset_heap, *old_vers_heap,
old_vers, NULL, nullptr);
return (err);
}
/** Builds the last committed version of a clustered index record for a
semi-consistent read. */
static void row_sel_build_committed_vers_for_mysql(
dict_index_t *clust_index, /*!< in: clustered index */
row_prebuilt_t *prebuilt, /*!< in: prebuilt struct */
const rec_t *rec, /*!< in: record in a clustered index */
ulint **offsets, /*!< in/out: offsets returned by
rec_get_offsets(rec, clust_index) */
mem_heap_t **offset_heap, /*!< in/out: memory heap from which
the offsets are allocated */
const rec_t **old_vers, /*!< out: old version, or NULL if the
record does not exist in the view:
i.e., it was freshly inserted
afterwards */
const dtuple_t **vrow, /*!< out: to be filled with old virtual
column version if any */
mtr_t *mtr) /*!< in: mtr */
{
if (prebuilt->old_vers_heap) {
mem_heap_empty(prebuilt->old_vers_heap);
} else {
prebuilt->old_vers_heap = mem_heap_create(rec_offs_size(*offsets));
}
row_vers_build_for_semi_consistent_read(rec, mtr, clust_index, offsets,
offset_heap, prebuilt->old_vers_heap,
old_vers, vrow);
}
/** Tests the conditions which determine when the index segment we are searching
through has been exhausted.
@return true if row passed the tests */
UNIV_INLINE
ibool row_sel_test_end_conds(
plan_t *plan) /*!< in: plan for the table; the column values must
already have been retrieved and the right sides of
comparisons evaluated */
{
func_node_t *cond;
/* All conditions in end_conds are comparisons of a column to an
expression */
for (cond = UT_LIST_GET_FIRST(plan->end_conds); cond != 0;
cond = UT_LIST_GET_NEXT(cond_list, cond)) {
/* Evaluate the left side of the comparison, i.e., get the
column value if there is an indirection */
eval_sym(static_cast<sym_node_t *>(cond->args));
/* Do the comparison */
if (!eval_cmp(cond)) {
return (FALSE);
}
}
return (TRUE);
}
/** Tests the other conditions.
@return true if row passed the tests */
UNIV_INLINE
ibool row_sel_test_other_conds(
plan_t *plan) /*!< in: plan for the table; the column values must
already have been retrieved */
{
func_node_t *cond;
cond = UT_LIST_GET_FIRST(plan->other_conds);
while (cond) {
eval_exp(cond);
if (!eval_node_get_ibool_val(cond)) {
return (FALSE);
}
cond = UT_LIST_GET_NEXT(cond_list, cond);
}
return (TRUE);
}
/** Retrieves the clustered index record corresponding to a record in a
non-clustered index. Does the necessary locking.
@return DB_SUCCESS or error code */
static MY_ATTRIBUTE((warn_unused_result)) dberr_t row_sel_get_clust_rec(
sel_node_t *node, /*!< in: select_node */
plan_t *plan, /*!< in: plan node for table */
rec_t *rec, /*!< in: record in a non-clustered index */
que_thr_t *thr, /*!< in: query thread */
rec_t **out_rec, /*!< out: clustered record or an old version of
it, NULL if the old version did not exist
in the read view, i.e., it was a fresh
inserted version */
mtr_t *mtr) /*!< in: mtr used to get access to the
non-clustered record; the same mtr is used to
access the clustered index */
{
dict_index_t *index;
rec_t *clust_rec;
rec_t *old_vers;
dberr_t err;
mem_heap_t *heap = NULL;
ulint offsets_[REC_OFFS_NORMAL_SIZE];
ulint *offsets = offsets_;
rec_offs_init(offsets_);
*out_rec = NULL;
offsets = rec_get_offsets(rec, btr_pcur_get_btr_cur(&plan->pcur)->index,
offsets, ULINT_UNDEFINED, &heap);
row_build_row_ref_fast(plan->clust_ref, plan->clust_map, rec, offsets);
index = plan->table->first_index();
btr_pcur_open_with_no_init(index, plan->clust_ref, PAGE_CUR_LE,
BTR_SEARCH_LEAF, &plan->clust_pcur, 0, mtr);
clust_rec = btr_pcur_get_rec(&(plan->clust_pcur));
/* Note: only if the search ends up on a non-infimum record is the
low_match value the real match to the search tuple */
if (!page_rec_is_user_rec(clust_rec) ||
btr_pcur_get_low_match(&(plan->clust_pcur)) <
dict_index_get_n_unique(index)) {
ut_a(rec_get_deleted_flag(rec, dict_table_is_comp(plan->table)));
ut_a(node->vision);
/* In a rare case it is possible that no clust rec is found
for a delete-marked secondary index record: if in row0umod.cc
in row_undo_mod_remove_clust_low() we have already removed
the clust rec, while purge is still cleaning and removing
secondary index records associated with earlier versions of
the clustered index record. In that case we know that the
clustered index record did not exist in the read view of
trx. */
goto func_exit;
}
offsets = rec_get_offsets(clust_rec, index, offsets, ULINT_UNDEFINED, &heap);
if (!node->vision) {
/* Try to place a lock on the index record */
ulint lock_type;
trx_t *trx;
trx = thr_get_trx(thr);
lock_type = trx->skip_gap_locks() ? LOCK_REC_NOT_GAP : LOCK_ORDINARY;
err = lock_clust_rec_read_check_and_lock(
lock_duration_t::REGULAR, btr_pcur_get_block(&plan->clust_pcur),
clust_rec, index, offsets, SELECT_ORDINARY,
static_cast<lock_mode>(node->row_lock_mode), lock_type, thr);
switch (err) {
case DB_SUCCESS:
case DB_SUCCESS_LOCKED_REC:
/* Declare the variable uninitialized in Valgrind.
It should be set to DB_SUCCESS at func_exit. */
UNIV_MEM_INVALID(&err, sizeof err);
break;
default:
goto err_exit;
}
} else {
/* This is a non-locking consistent read: if necessary, fetch
a previous version of the record */
old_vers = NULL;
if (!lock_clust_rec_cons_read_sees(clust_rec, index, offsets,
/** TODO: Add cleanout logic */
nullptr, node->vision)) {
err =
row_sel_build_prev_vers(node->vision, index, clust_rec, &offsets,
&heap, &plan->old_vers_heap, &old_vers, mtr);
if (err != DB_SUCCESS) {
goto err_exit;
}
clust_rec = old_vers;
if (clust_rec == NULL) {
goto func_exit;
}
}
/* If we had to go to an earlier version of row or the
secondary index record is delete marked, then it may be that
the secondary index record corresponding to clust_rec
(or old_vers) is not rec; in that case we must ignore
such row because in our snapshot rec would not have existed.
Remember that from rec we cannot see directly which transaction
id corresponds to it: we have to go to the clustered index
record. A query where we want to fetch all rows where
the secondary index value is in some interval would return
a wrong result if we would not drop rows which we come to
visit through secondary index records that would not really
exist in our snapshot. */
if (old_vers ||
rec_get_deleted_flag(rec, dict_table_is_comp(plan->table))) {
bool rec_equal;
err = row_sel_sec_rec_is_for_clust_rec(rec, plan->index, clust_rec, index,
thr, rec_equal);
if (err != DB_SUCCESS) {
goto err_exit;
} else if (!rec_equal) {
goto func_exit;
}
}
}
/* Fetch the columns needed in test conditions. The clustered
index record is protected by a page latch that was acquired
when plan->clust_pcur was positioned. The latch will not be
released until mtr_commit(mtr). */
ut_ad(!rec_get_deleted_flag(clust_rec, rec_offs_comp(offsets)));
row_sel_fetch_columns(thr_get_trx(thr), index, clust_rec, offsets,
UT_LIST_GET_FIRST(plan->columns));
*out_rec = clust_rec;
func_exit:
err = DB_SUCCESS;
err_exit:
if (UNIV_LIKELY_NULL(heap)) {
mem_heap_free(heap);
}
return (err);
}
/** Sets a lock on a page of R-Tree record. This is all or none action,
mostly due to we cannot reposition a record in R-Tree (with the
nature of splitting)
@param[in] pcur cursor
@param[in] first_rec record
@param[in] index index
@param[in] offsets rec_get_offsets(rec, index)
@param[in] sel_mode select mode: SELECT_ORDINARY,
SELECT_SKIP_LOKCED, or SELECT_NO_WAIT
@param[in] mode lock mode
@param[in] type LOCK_ORDINARY, LOCK_GAP, or LOC_REC_NOT_GAP
@param[in] thr query thread
@param[in] mtr mtr
@return DB_SUCCESS, DB_SUCCESS_LOCKED_REC, or error code */
UNIV_INLINE
dberr_t sel_set_rtr_rec_lock(btr_pcur_t *pcur, const rec_t *first_rec,
dict_index_t *index, const ulint *offsets,
select_mode sel_mode, ulint mode, ulint type,
que_thr_t *thr, mtr_t *mtr) {
matched_rec_t *match = pcur->m_btr_cur.rtr_info->matches;
mem_heap_t *heap = NULL;
dberr_t err = DB_SUCCESS;
trx_t *trx = thr_get_trx(thr);
buf_block_t *cur_block = btr_pcur_get_block(pcur);
ulint offsets_[REC_OFFS_NORMAL_SIZE];
ulint *my_offsets = const_cast<ulint *>(offsets);
rec_t *rec = const_cast<rec_t *>(first_rec);
rtr_rec_vector *match_rec;
rtr_rec_vector::iterator end;
rec_offs_init(offsets_);
if (match->locked || page_rec_is_supremum(first_rec)) {
return (DB_SUCCESS_LOCKED_REC);
}
ut_ad(page_align(first_rec) == cur_block->frame);
ut_ad(match->valid);
rw_lock_x_lock(&(match->block.lock));
retry:
cur_block = btr_pcur_get_block(pcur);
ut_ad(rw_lock_own(&(match->block.lock), RW_LOCK_X) ||
rw_lock_own(&(match->block.lock), RW_LOCK_S));
ut_ad(page_is_leaf(buf_block_get_frame(cur_block)));
err = lock_sec_rec_read_check_and_lock(
lock_duration_t::REGULAR, cur_block, rec, index, my_offsets, sel_mode,
static_cast<lock_mode>(mode), type, thr);
switch (err) {
case DB_SUCCESS:
case DB_SUCCESS_LOCKED_REC:
case DB_SKIP_LOCKED:
goto lock_match;
case DB_LOCK_WAIT:
re_scan:
mtr_commit(mtr);
trx->error_state = err;
que_thr_stop_for_mysql(thr);
thr->lock_state = QUE_THR_LOCK_ROW;
if (row_mysql_handle_errors(&err, trx, thr, NULL)) {
thr->lock_state = QUE_THR_LOCK_NOLOCK;
mtr_start(mtr);
mutex_enter(&match->rtr_match_mutex);
if (!match->valid && match->matched_recs->empty()) {
mutex_exit(&match->rtr_match_mutex);
err = DB_RECORD_NOT_FOUND;
goto func_end;
}
mutex_exit(&match->rtr_match_mutex);
page_no_t page_no = page_get_page_no(btr_pcur_get_page(pcur));
page_id_t page_id(dict_index_get_space(index), page_no);
cur_block = buf_page_get_gen(
page_id, dict_table_page_size(index->table), RW_X_LATCH, NULL,
Page_fetch::NORMAL, __FILE__, __LINE__, mtr);
} else {
mtr_start(mtr);
goto func_end;
}
DEBUG_SYNC_C("rtr_set_lock_wait");
if (!match->valid) {
/* Page got deleted */
mtr_commit(mtr);
mtr_start(mtr);
err = DB_RECORD_NOT_FOUND;
goto func_end;
}
match->matched_recs->clear();
rtr_cur_search_with_match(
cur_block, index, pcur->m_btr_cur.rtr_info->search_tuple,
pcur->m_btr_cur.rtr_info->search_mode, &pcur->m_btr_cur.page_cur,
pcur->m_btr_cur.rtr_info);
if (!page_is_leaf(buf_block_get_frame(cur_block))) {
/* Page got splitted and promoted (only for
root page it is possible). Release the
page and ask for a re-search */
mtr_commit(mtr);
mtr_start(mtr);
err = DB_RECORD_NOT_FOUND;
goto func_end;
}
rec = btr_pcur_get_rec(pcur);
my_offsets = offsets_;
my_offsets =
rec_get_offsets(rec, index, my_offsets, ULINT_UNDEFINED, &heap);
/* No match record */
if (page_rec_is_supremum(rec) || !match->valid) {
mtr_commit(mtr);
mtr_start(mtr);
err = DB_RECORD_NOT_FOUND;
goto func_end;
}
goto retry;
default:
goto func_end;
}
lock_match:
my_offsets = offsets_;
match_rec = match->matched_recs;
end = match_rec->end();
for (rtr_rec_vector::iterator it = match_rec->begin(); it != end; ++it) {
rtr_rec_t *rtr_rec = &(*it);
my_offsets = rec_get_offsets(rtr_rec->r_rec, index, my_offsets,
ULINT_UNDEFINED, &heap);
err = lock_sec_rec_read_check_and_lock(
lock_duration_t::REGULAR, &match->block, rtr_rec->r_rec, index,
my_offsets, sel_mode, static_cast<lock_mode>(mode), type, thr);
switch (err) {
case DB_SUCCESS:
case DB_SUCCESS_LOCKED_REC:
rtr_rec->locked = true;
break;
case DB_LOCK_WAIT:
goto re_scan;
case DB_SKIP_LOCKED:
break;
default:
goto func_end;
}
}
match->locked = true;
func_end:
rw_lock_x_unlock(&(match->block.lock));
if (heap != NULL) {
mem_heap_free(heap);
}
ut_ad(err != DB_LOCK_WAIT);
return (err);
}
/** Sets a lock on a record.
mostly due to we cannot reposition a record in R-Tree (with the
nature of splitting)
@param[in] pcur cursor
@param[in] rec record
@param[in] index index
@param[in] offsets rec_get_offsets(rec, index)
@param[in] sel_mode select mode: SELECT_ORDINARY,
SELECT_SKIP_LOKCED, or SELECT_NO_WAIT
@param[in] mode lock mode
@param[in] type LOCK_ORDINARY, LOCK_GAP, or LOC_REC_NOT_GAP
@param[in] thr query thread
@param[in] mtr mtr
@return DB_SUCCESS, DB_SUCCESS_LOCKED_REC, or error code */
UNIV_INLINE
dberr_t sel_set_rec_lock(btr_pcur_t *pcur, const rec_t *rec,
dict_index_t *index, const ulint *offsets,
select_mode sel_mode, ulint mode, ulint type,
que_thr_t *thr, mtr_t *mtr) {
trx_t *trx;
dberr_t err = DB_SUCCESS;
const buf_block_t *block;
block = btr_pcur_get_block(pcur);
trx = thr_get_trx(thr);
trx_mutex_enter(trx);
bool too_many_locks = (UT_LIST_GET_LEN(trx->lock.trx_locks) > 10000);
trx_mutex_exit(trx);
if (too_many_locks) {
if (buf_LRU_buf_pool_running_out()) {
return (DB_LOCK_TABLE_FULL);
}
}
if (index->is_clustered()) {
err = lock_clust_rec_read_check_and_lock(
lock_duration_t::REGULAR, block, rec, index, offsets, sel_mode,
static_cast<lock_mode>(mode), type, thr);
} else {
if (dict_index_is_spatial(index)) {
if (type == LOCK_GAP || type == LOCK_ORDINARY) {
ut_ad(0);
ib::error(ER_IB_MSG_1026) << "Incorrectly request GAP lock "
"on RTree";
return (DB_SUCCESS);
}
err = sel_set_rtr_rec_lock(pcur, rec, index, offsets, sel_mode, mode,
type, thr, mtr);
} else {
err = lock_sec_rec_read_check_and_lock(
lock_duration_t::REGULAR, block, rec, index, offsets, sel_mode,
static_cast<lock_mode>(mode), type, thr);
}
}
return (err);
}
/** Opens a pcur to a table index. */
static void row_sel_open_pcur(plan_t *plan, /*!< in: table plan */
ibool search_latch_locked,
/*!< in: TRUE if the thread currently
has the search latch locked in
s-mode */
mtr_t *mtr) /*!< in: mtr */
{
dict_index_t *index;
func_node_t *cond;
que_node_t *exp;
ulint n_fields;
ulint has_search_latch = 0; /* RW_S_LATCH or 0 */
ulint i;
if (search_latch_locked) {
has_search_latch = RW_S_LATCH;
}
index = plan->index;
/* Calculate the value of the search tuple: the exact match columns
get their expressions evaluated when we evaluate the right sides of
end_conds */
cond = UT_LIST_GET_FIRST(plan->end_conds);
while (cond) {
eval_exp(que_node_get_next(cond->args));
cond = UT_LIST_GET_NEXT(cond_list, cond);
}
if (plan->tuple) {
n_fields = dtuple_get_n_fields(plan->tuple);
if (plan->n_exact_match < n_fields) {
/* There is a non-exact match field which must be
evaluated separately */
eval_exp(plan->tuple_exps[n_fields - 1]);
}
for (i = 0; i < n_fields; i++) {
exp = plan->tuple_exps[i];
dfield_copy_data(dtuple_get_nth_field(plan->tuple, i),
que_node_get_val(exp));
}
/* Open pcur to the index */
btr_pcur_open_with_no_init(index, plan->tuple, plan->mode, BTR_SEARCH_LEAF,
&plan->pcur, has_search_latch, mtr);
} else {
/* Open the cursor to the start or the end of the index
(FALSE: no init) */
btr_pcur_open_at_index_side(plan->asc, index, BTR_SEARCH_LEAF,
&(plan->pcur), false, 0, mtr);
}
ut_ad(plan->n_rows_prefetched == 0);
ut_ad(plan->n_rows_fetched == 0);
ut_ad(plan->cursor_at_end == FALSE);
plan->pcur_is_open = TRUE;
}
/** Restores a stored pcur position to a table index.
@return true if the cursor should be moved to the next record after we
return from this function (moved to the previous, in the case of a
descending cursor) without processing again the current cursor
record */
static ibool row_sel_restore_pcur_pos(plan_t *plan, /*!< in: table plan */
mtr_t *mtr) /*!< in: mtr */
{
ibool equal_position;
ulint relative_position;
ut_ad(!plan->cursor_at_end);
relative_position = btr_pcur_get_rel_pos(&(plan->pcur));
equal_position =
btr_pcur_restore_position(BTR_SEARCH_LEAF, &(plan->pcur), mtr);
/* If the cursor is traveling upwards, and relative_position is
(1) BTR_PCUR_BEFORE: this is not allowed, as we did not have a lock
yet on the successor of the page infimum;
(2) BTR_PCUR_AFTER: btr_pcur_restore_position placed the cursor on the
first record GREATER than the predecessor of a page supremum; we have
not yet processed the cursor record: no need to move the cursor to the
next record;
(3) BTR_PCUR_ON: btr_pcur_restore_position placed the cursor on the
last record LESS or EQUAL to the old stored user record; (a) if
equal_position is FALSE, this means that the cursor is now on a record
less than the old user record, and we must move to the next record;
(b) if equal_position is TRUE, then if
plan->stored_cursor_rec_processed is TRUE, we must move to the next
record, else there is no need to move the cursor. */
if (plan->asc) {
if (relative_position == BTR_PCUR_ON) {
if (equal_position) {
return (plan->stored_cursor_rec_processed);
}
return (TRUE);
}
ut_ad(relative_position == BTR_PCUR_AFTER ||
relative_position == BTR_PCUR_AFTER_LAST_IN_TREE);
return (FALSE);
}
/* If the cursor is traveling downwards, and relative_position is
(1) BTR_PCUR_BEFORE: btr_pcur_restore_position placed the cursor on
the last record LESS than the successor of a page infimum; we have not
processed the cursor record: no need to move the cursor;
(2) BTR_PCUR_AFTER: btr_pcur_restore_position placed the cursor on the
first record GREATER than the predecessor of a page supremum; we have
processed the cursor record: we should move the cursor to the previous
record;
(3) BTR_PCUR_ON: btr_pcur_restore_position placed the cursor on the
last record LESS or EQUAL to the old stored user record; (a) if
equal_position is FALSE, this means that the cursor is now on a record
less than the old user record, and we need not move to the previous
record; (b) if equal_position is TRUE, then if
plan->stored_cursor_rec_processed is TRUE, we must move to the previous
record, else there is no need to move the cursor. */
if (relative_position == BTR_PCUR_BEFORE ||
relative_position == BTR_PCUR_BEFORE_FIRST_IN_TREE) {
return (FALSE);
}
if (relative_position == BTR_PCUR_ON) {
if (equal_position) {
return (plan->stored_cursor_rec_processed);
}
return (FALSE);
}
ut_ad(relative_position == BTR_PCUR_AFTER ||
relative_position == BTR_PCUR_AFTER_LAST_IN_TREE);
return (TRUE);
}
/** Resets a plan cursor to a closed state. */
UNIV_INLINE
void plan_reset_cursor(plan_t *plan) /*!< in: plan */
{
plan->pcur_is_open = FALSE;
plan->cursor_at_end = FALSE;
plan->n_rows_fetched = 0;
plan->n_rows_prefetched = 0;
}
/** Tries to do a shortcut to fetch a clustered index record with a unique key,
using the hash index if possible (not always).
@return SEL_FOUND, SEL_EXHAUSTED, SEL_RETRY */
static ulint row_sel_try_search_shortcut(
trx_t *trx, /*!< in: trx doing the operation. */
sel_node_t *node, /*!< in: select node for a consistent read */
plan_t *plan, /*!< in: plan for a unique search in clustered
index */
ibool search_latch_locked,
/*!< in: whether the search holds latch on
search system. */
mtr_t *mtr) /*!< in: mtr */
{
dict_index_t *index;
rec_t *rec;
mem_heap_t *heap = NULL;
ulint offsets_[REC_OFFS_NORMAL_SIZE];
ulint *offsets = offsets_;
ulint ret;
rec_offs_init(offsets_);
index = plan->index;
ut_ad(node->vision);
ut_ad(plan->unique_search);
ut_ad(!plan->must_get_clust);
#ifdef UNIV_DEBUG
if (search_latch_locked) {
ut_ad(rw_lock_own(btr_get_search_latch(index), RW_LOCK_S));
}
#endif /* UNIV_DEBUG */
row_sel_open_pcur(plan, search_latch_locked, mtr);
rec = btr_pcur_get_rec(&(plan->pcur));
if (!page_rec_is_user_rec(rec)) {
return (SEL_RETRY);
}
ut_ad(plan->mode == PAGE_CUR_GE);
/* As the cursor is now placed on a user record after a search with
the mode PAGE_CUR_GE, the up_match field in the cursor tells how many
fields in the user record matched to the search tuple */
if (btr_pcur_get_up_match(&(plan->pcur)) < plan->n_exact_match) {
return (SEL_EXHAUSTED);
}
/* This is a non-locking consistent read: if necessary, fetch
a previous version of the record */
offsets = rec_get_offsets(rec, index, offsets, ULINT_UNDEFINED, &heap);
if (index->is_clustered()) {
if (!lock_clust_rec_cons_read_sees(rec, index, offsets,
/**TODO: Add cleanout logic */
nullptr, node->vision)) {
ret = SEL_RETRY;
goto func_exit;
}
} else if (!srv_read_only_mode &&
!lock_sec_rec_cons_read_sees(rec, index, node->vision)) {
ret = SEL_RETRY;
goto func_exit;
}
/* Test the deleted flag. */
if (rec_get_deleted_flag(rec, dict_table_is_comp(plan->table))) {
ret = SEL_EXHAUSTED;
goto func_exit;
}
/* Fetch the columns needed in test conditions. The index
record is protected by a page latch that was acquired when
plan->pcur was positioned. The latch will not be released
until mtr_commit(mtr). */
row_sel_fetch_columns(trx, index, rec, offsets,
UT_LIST_GET_FIRST(plan->columns));
/* Test the rest of search conditions */
if (!row_sel_test_other_conds(plan)) {
ret = SEL_EXHAUSTED;
goto func_exit;
}
ut_ad(plan->pcur.m_latch_mode == BTR_SEARCH_LEAF);
plan->n_rows_fetched++;
ret = SEL_FOUND;
func_exit:
if (UNIV_LIKELY_NULL(heap)) {
mem_heap_free(heap);
}
return (ret);
}
/** Performs a select step.
@return DB_SUCCESS or error code */
static MY_ATTRIBUTE((warn_unused_result)) dberr_t
row_sel(sel_node_t *node, /*!< in: select node */
que_thr_t *thr) /*!< in: query thread */
{
dict_index_t *index;
plan_t *plan;
mtr_t mtr;
ibool moved;
rec_t *rec;
rec_t *old_vers;
rec_t *clust_rec;
ibool search_latch_locked;
ibool consistent_read;
/* The following flag becomes TRUE when we are doing a
consistent read from a non-clustered index and we must look
at the clustered index to find out the previous delete mark
state of the non-clustered record: */
ibool cons_read_requires_clust_rec = FALSE;
ulint cost_counter = 0;
ibool cursor_just_opened;
ibool must_go_to_next;
ibool mtr_has_extra_clust_latch = FALSE;
/* TRUE if the search was made using
a non-clustered index, and we had to
access the clustered record: now &mtr
contains a clustered index latch, and
&mtr must be committed before we move
to the next non-clustered record */
ulint found_flag;
dberr_t err;
mem_heap_t *heap = NULL;
ulint offsets_[REC_OFFS_NORMAL_SIZE];
ulint *offsets = offsets_;
rec_offs_init(offsets_);
ut_ad(thr->run_node == node);
search_latch_locked = FALSE;
if (node->vision) {
/* In consistent reads, we try to do with the hash index and
not to use the buffer page get. This is to reduce memory bus
load resulting from semaphore operations. The search latch
will be s-locked when we access an index with a unique search
condition, but not locked when we access an index with a
less selective search condition. */
consistent_read = TRUE;
} else {
consistent_read = FALSE;
}
table_loop:
/* TABLE LOOP
----------
This is the outer major loop in calculating a join. We come here when
node->fetch_table changes, and after adding a row to aggregate totals
and, of course, when this function is called. */
ut_ad(mtr_has_extra_clust_latch == FALSE);
plan = sel_node_get_nth_plan(node, node->fetch_table);
index = plan->index;
if (plan->n_rows_prefetched > 0) {
sel_dequeue_prefetched_row(plan);
goto next_table_no_mtr;
}
if (plan->cursor_at_end) {
/* The cursor has already reached the result set end: no more
rows to process for this table cursor, as also the prefetch
stack was empty */
ut_ad(plan->pcur_is_open);
goto table_exhausted_no_mtr;
}
/* Open a cursor to index, or restore an open cursor position */
mtr_start(&mtr);
if (consistent_read && plan->unique_search && !plan->pcur_is_open &&
!plan->must_get_clust && !plan->table->big_rows) {
if (!search_latch_locked) {
rw_lock_s_lock(btr_get_search_latch(index));
search_latch_locked = TRUE;
} else if (rw_lock_get_writer(btr_get_search_latch(index)) ==
RW_LOCK_X_WAIT) {
/* There is an x-latch request waiting: release the
s-latch for a moment; as an s-latch here is often
kept for some 10 searches before being released,
a waiting x-latch request would block other threads
from acquiring an s-latch for a long time, lowering
performance significantly in multiprocessors. */
rw_lock_s_unlock(btr_get_search_latch(index));
rw_lock_s_lock(btr_get_search_latch(index));
}
found_flag = row_sel_try_search_shortcut(thr_get_trx(thr), node, plan,
search_latch_locked, &mtr);
if (found_flag == SEL_FOUND) {
goto next_table;
} else if (found_flag == SEL_EXHAUSTED) {
goto table_exhausted;
}
ut_ad(found_flag == SEL_RETRY);
plan_reset_cursor(plan);
mtr_commit(&mtr);
mtr_start(&mtr);
}
if (search_latch_locked) {
rw_lock_s_unlock(btr_get_search_latch(index));
search_latch_locked = FALSE;
}
if (!plan->pcur_is_open) {
/* Evaluate the expressions to build the search tuple and
open the cursor */
row_sel_open_pcur(plan, search_latch_locked, &mtr);
cursor_just_opened = TRUE;
/* A new search was made: increment the cost counter */
cost_counter++;
} else {
/* Restore pcur position to the index */
must_go_to_next = row_sel_restore_pcur_pos(plan, &mtr);
cursor_just_opened = FALSE;
if (must_go_to_next) {
/* We have already processed the cursor record: move
to the next */
goto next_rec;
}
}
rec_loop:
/* RECORD LOOP
-----------
In this loop we use pcur and try to fetch a qualifying row, and
also fill the prefetch buffer for this table if n_rows_fetched has
exceeded a threshold. While we are inside this loop, the following
holds:
(1) &mtr is started,
(2) pcur is positioned and open.
NOTE that if cursor_just_opened is TRUE here, it means that we came
to this point right after row_sel_open_pcur. */
ut_ad(mtr_has_extra_clust_latch == FALSE);
rec = btr_pcur_get_rec(&(plan->pcur));
/* PHASE 1: Set a lock if specified */
if (!node->asc && cursor_just_opened && !page_rec_is_supremum(rec)) {
/* Do not support "descending search" for Spatial index */
ut_ad(!dict_index_is_spatial(index));
/* When we open a cursor for a descending search, we must set
a next-key lock on the successor record: otherwise it would
be possible to insert new records next to the cursor position,
and it might be that these new records should appear in the
search result set, resulting in the phantom problem. */
if (!consistent_read) {
rec_t *next_rec = page_rec_get_next(rec);
ulint lock_type;
trx_t *trx;
trx = thr_get_trx(thr);
offsets =
rec_get_offsets(next_rec, index, offsets, ULINT_UNDEFINED, &heap);
if (trx->skip_gap_locks()) {
if (page_rec_is_supremum(next_rec)) {
goto skip_lock;
}
lock_type = LOCK_REC_NOT_GAP;
} else {
lock_type = LOCK_ORDINARY;
}
err = sel_set_rec_lock(&plan->pcur, next_rec, index, offsets,
SELECT_ORDINARY, node->row_lock_mode, lock_type,
thr, &mtr);
switch (err) {
case DB_SUCCESS_LOCKED_REC:
err = DB_SUCCESS;
case DB_SUCCESS:
break;
default:
/* Note that in this case we will store in pcur
the PREDECESSOR of the record we are waiting
the lock for */
goto lock_wait_or_error;
}
}
}
skip_lock:
if (page_rec_is_infimum(rec)) {
/* The infimum record on a page cannot be in the result set,
and neither can a record lock be placed on it: we skip such
a record. We also increment the cost counter as we may have
processed yet another page of index. */
cost_counter++;
goto next_rec;
}
if (!consistent_read) {
/* Try to place a lock on the index record */
ulint lock_type;
trx_t *trx;
offsets = rec_get_offsets(rec, index, offsets, ULINT_UNDEFINED, &heap);
trx = thr_get_trx(thr);
if (trx->skip_gap_locks() || dict_index_is_spatial(index)) {
if (page_rec_is_supremum(rec)) {
goto next_rec;
}
lock_type = LOCK_REC_NOT_GAP;
} else {
lock_type = LOCK_ORDINARY;
}
err = sel_set_rec_lock(&plan->pcur, rec, index, offsets, SELECT_ORDINARY,
node->row_lock_mode, lock_type, thr, &mtr);
switch (err) {
case DB_SUCCESS_LOCKED_REC:
err = DB_SUCCESS;
case DB_SUCCESS:
break;
default:
goto lock_wait_or_error;
}
}
if (page_rec_is_supremum(rec)) {
/* A page supremum record cannot be in the result set: skip
it now when we have placed a possible lock on it */
goto next_rec;
}
ut_ad(page_rec_is_user_rec(rec));
if (cost_counter > SEL_COST_LIMIT) {
/* Now that we have placed the necessary locks, we can stop
for a while and store the cursor position; NOTE that if we
would store the cursor position BEFORE placing a record lock,
it might happen that the cursor would jump over some records
that another transaction could meanwhile insert adjacent to
the cursor: this would result in the phantom problem. */
goto stop_for_a_while;
}
/* PHASE 2: Check a mixed index mix id if needed */
if (plan->unique_search && cursor_just_opened) {
ut_ad(plan->mode == PAGE_CUR_GE);
/* As the cursor is now placed on a user record after a search
with the mode PAGE_CUR_GE, the up_match field in the cursor
tells how many fields in the user record matched to the search
tuple */
if (btr_pcur_get_up_match(&(plan->pcur)) < plan->n_exact_match) {
goto table_exhausted;
}
/* Ok, no need to test end_conds or mix id */
}
/* We are ready to look at a possible new index entry in the result
set: the cursor is now placed on a user record */
/* PHASE 3: Get previous version in a consistent read */
cons_read_requires_clust_rec = FALSE;
offsets = rec_get_offsets(rec, index, offsets, ULINT_UNDEFINED, &heap);
if (consistent_read) {
/* This is a non-locking consistent read: if necessary, fetch
a previous version of the record */
if (index->is_clustered()) {
if (!lock_clust_rec_cons_read_sees(rec, index, offsets,
/**TODO: cleanout logic */
nullptr, node->vision)) {
err = row_sel_build_prev_vers(node->vision, index, rec, &offsets,
&heap, &plan->old_vers_heap, &old_vers,
&mtr);
if (err != DB_SUCCESS) {
goto lock_wait_or_error;
}
if (old_vers == NULL) {
/* The record does not exist
in our read view. Skip it, but
first attempt to determine
whether the index segment we
are searching through has been
exhausted. */
offsets =
rec_get_offsets(rec, index, offsets, ULINT_UNDEFINED, &heap);
/* Fetch the columns needed in
test conditions. The clustered
index record is protected by a
page latch that was acquired
by row_sel_open_pcur() or
row_sel_restore_pcur_pos().
The latch will not be released
until mtr_commit(mtr). */
row_sel_fetch_columns(thr_get_trx(thr), index, rec, offsets,
UT_LIST_GET_FIRST(plan->columns));
if (!row_sel_test_end_conds(plan)) {
goto table_exhausted;
}
goto next_rec;
}
rec = old_vers;
}
} else if (!srv_read_only_mode &&
!lock_sec_rec_cons_read_sees(rec, index, node->vision)) {
cons_read_requires_clust_rec = TRUE;
}
}
/* PHASE 4: Test search end conditions and deleted flag */
/* Fetch the columns needed in test conditions. The record is
protected by a page latch that was acquired by
row_sel_open_pcur() or row_sel_restore_pcur_pos(). The latch
will not be released until mtr_commit(mtr). */
row_sel_fetch_columns(thr_get_trx(thr), index, rec, offsets,
UT_LIST_GET_FIRST(plan->columns));
/* Test the selection end conditions: these can only contain columns
which already are found in the index, even though the index might be
non-clustered */
if (plan->unique_search && cursor_just_opened) {
/* No test necessary: the test was already made above */
} else if (!row_sel_test_end_conds(plan)) {
goto table_exhausted;
}
if (rec_get_deleted_flag(rec, dict_table_is_comp(plan->table)) &&
!cons_read_requires_clust_rec) {
/* The record is delete marked: we can skip it if this is
not a consistent read which might see an earlier version
of a non-clustered index record */
if (plan->unique_search) {
goto table_exhausted;
}
goto next_rec;
}
/* PHASE 5: Get the clustered index record, if needed and if we did
not do the search using the clustered index */
if (plan->must_get_clust || cons_read_requires_clust_rec) {
/* It was a non-clustered index and we must fetch also the
clustered index record */
err = row_sel_get_clust_rec(node, plan, rec, thr, &clust_rec, &mtr);
mtr_has_extra_clust_latch = TRUE;
if (err != DB_SUCCESS) {
goto lock_wait_or_error;
}
/* Retrieving the clustered record required a search:
increment the cost counter */
cost_counter++;
if (clust_rec == NULL) {
/* The record did not exist in the read view */
ut_ad(consistent_read);
goto next_rec;
}
if (rec_get_deleted_flag(clust_rec, dict_table_is_comp(plan->table))) {
/* The record is delete marked: we can skip it */
goto next_rec;
}
if (node->can_get_updated) {
btr_pcur_store_position(&(plan->clust_pcur), &mtr);
}
}
/* PHASE 6: Test the rest of search conditions */
if (!row_sel_test_other_conds(plan)) {
if (plan->unique_search) {
goto table_exhausted;
}
goto next_rec;
}
/* PHASE 7: We found a new qualifying row for the current table; push
the row if prefetch is on, or move to the next table in the join */
plan->n_rows_fetched++;
ut_ad(plan->pcur.m_latch_mode == BTR_SEARCH_LEAF);
if ((plan->n_rows_fetched <= SEL_PREFETCH_LIMIT) || plan->unique_search ||
plan->no_prefetch || plan->table->big_rows) {
/* No prefetch in operation: go to the next table */
goto next_table;
}
sel_enqueue_prefetched_row(plan);
if (plan->n_rows_prefetched == SEL_MAX_N_PREFETCH) {
/* The prefetch buffer is now full */
sel_dequeue_prefetched_row(plan);
goto next_table;
}
next_rec:
ut_ad(!search_latch_locked);
if (mtr_has_extra_clust_latch) {
/* We must commit &mtr if we are moving to the next
non-clustered index record, because we could break the
latching order if we would access a different clustered
index page right away without releasing the previous. */
goto commit_mtr_for_a_while;
}
if (node->asc) {
moved = btr_pcur_move_to_next(&(plan->pcur), &mtr);
} else {
moved = btr_pcur_move_to_prev(&(plan->pcur), &mtr);
}
if (!moved) {
goto table_exhausted;
}
cursor_just_opened = FALSE;
/* END OF RECORD LOOP
------------------ */
goto rec_loop;
next_table:
/* We found a record which satisfies the conditions: we can move to
the next table or return a row in the result set */
ut_ad(btr_pcur_is_on_user_rec(&plan->pcur));
if (plan->unique_search && !node->can_get_updated) {
plan->cursor_at_end = TRUE;
} else {
ut_ad(!search_latch_locked);
plan->stored_cursor_rec_processed = TRUE;
btr_pcur_store_position(&(plan->pcur), &mtr);
}
mtr_commit(&mtr);
mtr_has_extra_clust_latch = FALSE;
next_table_no_mtr:
/* If we use 'goto' to this label, it means that the row was popped
from the prefetched rows stack, and &mtr is already committed */
if (node->fetch_table + 1 == node->n_tables) {
sel_eval_select_list(node);
if (node->is_aggregate) {
goto table_loop;
}
sel_assign_into_var_values(node->into_list, node);
thr->run_node = que_node_get_parent(node);
err = DB_SUCCESS;
goto func_exit;
}
node->fetch_table++;
/* When we move to the next table, we first reset the plan cursor:
we do not care about resetting it when we backtrack from a table */
plan_reset_cursor(sel_node_get_nth_plan(node, node->fetch_table));
goto table_loop;
table_exhausted:
/* The table cursor pcur reached the result set end: backtrack to the
previous table in the join if we do not have cached prefetched rows */
plan->cursor_at_end = TRUE;
mtr_commit(&mtr);
mtr_has_extra_clust_latch = FALSE;
if (plan->n_rows_prefetched > 0) {
/* The table became exhausted during a prefetch */
sel_dequeue_prefetched_row(plan);
goto next_table_no_mtr;
}
table_exhausted_no_mtr:
if (node->fetch_table == 0) {
err = DB_SUCCESS;
if (node->is_aggregate && !node->aggregate_already_fetched) {
node->aggregate_already_fetched = TRUE;
sel_assign_into_var_values(node->into_list, node);
thr->run_node = que_node_get_parent(node);
} else {
node->state = SEL_NODE_NO_MORE_ROWS;
thr->run_node = que_node_get_parent(node);
}
goto func_exit;
}
node->fetch_table--;
goto table_loop;
stop_for_a_while:
/* Return control for a while to que_run_threads, so that runaway
queries can be canceled. NOTE that when we come here, we must, in a
locking read, have placed the necessary (possibly waiting request)
record lock on the cursor record or its successor: when we reposition
the cursor, this record lock guarantees that nobody can meanwhile have
inserted new records which should have appeared in the result set,
which would result in the phantom problem. */
ut_ad(!search_latch_locked);
plan->stored_cursor_rec_processed = FALSE;
btr_pcur_store_position(&(plan->pcur), &mtr);
mtr_commit(&mtr);
#ifdef UNIV_DEBUG
{
btrsea_sync_check check(true);
ut_ad(!sync_check_iterate(check));
}
#endif /* UNIV_DEBUG */
err = DB_SUCCESS;
goto func_exit;
commit_mtr_for_a_while:
/* Stores the cursor position and commits &mtr; this is used if
&mtr may contain latches which would break the latching order if
&mtr would not be committed and the latches released. */
plan->stored_cursor_rec_processed = TRUE;
ut_ad(!search_latch_locked);
btr_pcur_store_position(&(plan->pcur), &mtr);
mtr_commit(&mtr);
mtr_has_extra_clust_latch = FALSE;
#ifdef UNIV_DEBUG
{
dict_sync_check check(true);
ut_ad(!sync_check_iterate(check));
}
#endif /* UNIV_DEBUG */
goto table_loop;
lock_wait_or_error:
/* See the note at stop_for_a_while: the same holds for this case */
ut_ad(!btr_pcur_is_before_first_on_page(&plan->pcur) || !node->asc);
ut_ad(!search_latch_locked);
plan->stored_cursor_rec_processed = FALSE;
btr_pcur_store_position(&(plan->pcur), &mtr);
mtr_commit(&mtr);
#ifdef UNIV_DEBUG
{
dict_sync_check check(true);
ut_ad(!sync_check_iterate(check));
}
#endif /* UNIV_DEBUG */
func_exit:
if (search_latch_locked) {
rw_lock_s_unlock(btr_get_search_latch(index));
}
if (heap != NULL) {
mem_heap_free(heap);
}
return (err);
}
/** Performs a select step. This is a high-level function used in SQL execution
graphs.
@return query thread to run next or NULL */
que_thr_t *row_sel_step(que_thr_t *thr) /*!< in: query thread */
{
sel_node_t *node;
ut_ad(thr);
node = static_cast<sel_node_t *>(thr->run_node);
ut_ad(que_node_get_type(node) == QUE_NODE_SELECT);
/* If this is a new time this node is executed (or when execution
resumes after wait for a table intention lock), set intention locks
on the tables, or assign a read view */
if (node->into_list && (thr->prev_node == que_node_get_parent(node))) {
node->state = SEL_NODE_OPEN;
}
if (node->state == SEL_NODE_OPEN) {
/* It may be that the current session has not yet started
its transaction, or it has been committed: */
trx_start_if_not_started_xa(thr_get_trx(thr), false);
plan_reset_cursor(sel_node_get_nth_plan(node, 0));
if (node->consistent_read) {
/* Assign a read view for the query */
trx_assign_read_view(thr_get_trx(thr));
if (thr_get_trx(thr)->vision.is_active()) {
node->vision = &thr_get_trx(thr)->vision;
} else {
node->vision = NULL;
}
} else {
sym_node_t *table_node;
lock_mode i_lock_mode;
if (node->set_x_locks) {
i_lock_mode = LOCK_IX;
} else {
i_lock_mode = LOCK_IS;
}
for (table_node = node->table_list; table_node != 0;
table_node =
static_cast<sym_node_t *>(que_node_get_next(table_node))) {
dberr_t err = lock_table(0, table_node->table, i_lock_mode, thr);
if (err != DB_SUCCESS) {
trx_t *trx;
trx = thr_get_trx(thr);
trx->error_state = err;
return (NULL);
}
}
}
/* If this is an explicit cursor, copy stored procedure
variable values, so that the values cannot change between
fetches (currently, we copy them also for non-explicit
cursors) */
if (node->explicit_cursor && UT_LIST_GET_FIRST(node->copy_variables)) {
row_sel_copy_input_variable_vals(node);
}
node->state = SEL_NODE_FETCH;
node->fetch_table = 0;
if (node->is_aggregate) {
/* Reset the aggregate total values */
sel_reset_aggregate_vals(node);
}
}
dberr_t err = row_sel(node, thr);
/* NOTE! if queries are parallelized, the following assignment may
have problems; the assignment should be made only if thr is the
only top-level thr in the graph: */
thr->graph->last_sel_node = node;
if (err != DB_SUCCESS) {
thr_get_trx(thr)->error_state = err;
return (NULL);
}
return (thr);
}
/** Performs a fetch for a cursor.
@return query thread to run next or NULL */
que_thr_t *fetch_step(que_thr_t *thr) /*!< in: query thread */
{
sel_node_t *sel_node;
fetch_node_t *node;
ut_ad(thr);
node = static_cast<fetch_node_t *>(thr->run_node);
sel_node = node->cursor_def;
ut_ad(que_node_get_type(node) == QUE_NODE_FETCH);
if (thr->prev_node != que_node_get_parent(node)) {
if (sel_node->state != SEL_NODE_NO_MORE_ROWS) {
if (node->into_list) {
sel_assign_into_var_values(node->into_list, sel_node);
} else {
ibool ret = (*node->func->func)(sel_node, node->func->arg);
if (!ret) {
sel_node->state = SEL_NODE_NO_MORE_ROWS;
}
}
}
thr->run_node = que_node_get_parent(node);
return (thr);
}
/* Make the fetch node the parent of the cursor definition for
the time of the fetch, so that execution knows to return to this
fetch node after a row has been selected or we know that there is
no row left */
sel_node->common.parent = node;
if (sel_node->state == SEL_NODE_CLOSED) {
ib::error(ER_IB_MSG_1027) << "fetch called on a closed cursor";
thr_get_trx(thr)->error_state = DB_ERROR;
return (NULL);
}
thr->run_node = sel_node;
return (thr);
}
/** Converts a key value stored in MySQL format to an Innobase dtuple. The last
field of the key value may be just a prefix of a fixed length field: hence
the parameter key_len. But currently we do not allow search keys where the
last field is only a prefix of the full key field len and print a warning if
such appears. A counterpart of this function is
ha_innobase::store_key_val_for_row() in ha_innodb.cc. */
void row_sel_convert_mysql_key_to_innobase(
dtuple_t *tuple, /*!< in/out: tuple where to build;
NOTE: we assume that the type info
in the tuple is already according
to index! */
byte *buf, /*!< in: buffer to use in field
conversions; NOTE that dtuple->data
may end up pointing inside buf so
do not discard that buffer while
the tuple is being used. See
row_mysql_store_col_in_innobase_format()
in the case of DATA_INT */
ulint buf_len, /*!< in: buffer length */
dict_index_t *index, /*!< in: index of the key value */
const byte *key_ptr, /*!< in: MySQL key value */
ulint key_len, /*!< in: MySQL key value length */
trx_t *trx) /*!< in: transaction */
{
byte *original_buf = buf;
const byte *original_key_ptr = key_ptr;
dict_field_t *field;
dfield_t *dfield;
ulint data_offset;
ulint data_len;
ulint data_field_len;
ibool is_null;
const byte *key_end;
ulint n_fields = 0;
/* For documentation of the key value storage format in MySQL, see
ha_innobase::store_key_val_for_row() in ha_innodb.cc. */
key_end = key_ptr + key_len;
/* Permit us to access any field in the tuple (ULINT_MAX): */
dtuple_set_n_fields(tuple, ULINT_MAX);
dfield = dtuple_get_nth_field(tuple, 0);
field = index->get_field(0);
if (UNIV_UNLIKELY(dfield_get_type(dfield)->mtype == DATA_SYS)) {
/* A special case: we are looking for a position in the
generated clustered index which InnoDB automatically added
to a table with no primary key: the first and the only
ordering column is ROW_ID which InnoDB stored to the key_ptr
buffer. */
ut_a(key_len == DATA_ROW_ID_LEN);
dfield_set_data(dfield, key_ptr, DATA_ROW_ID_LEN);
dtuple_set_n_fields(tuple, 1);
return;
}
while (key_ptr < key_end) {
ulint type = dfield_get_type(dfield)->mtype;
ut_a(field->col->mtype == type);
data_offset = 0;
is_null = FALSE;
if (!(dfield_get_type(dfield)->prtype & DATA_NOT_NULL)) {
/* The first byte in the field tells if this is
an SQL NULL value */
data_offset = 1;
if (*key_ptr != 0) {
dfield_set_null(dfield);
is_null = TRUE;
}
}
/* Calculate data length and data field total length */
if (DATA_LARGE_MTYPE(type) || DATA_GEOMETRY_MTYPE(type)) {
/* For R-tree index, data length should be the
total size of the wkb data.*/
if (dict_index_is_spatial(index)) {
ut_ad(DATA_GEOMETRY_MTYPE(type));
data_len = key_len;
data_field_len = data_offset + data_len;
} else {
/* The key field is a column prefix of a BLOB
or TEXT, except DATA_POINT of GEOMETRY. */
ut_a(field->prefix_len > 0 || DATA_POINT_MTYPE(type));
/* MySQL stores the actual data length to the
first 2 bytes after the optional SQL NULL
marker byte. The storage format is
little-endian, that is, the most significant
byte at a higher address. In UTF-8, MySQL
seems to reserve field->prefix_len bytes for
storing this field in the key value buffer,
even though the actual value only takes data
len bytes from the start.
For POINT of GEOMETRY, which has no prefix
because it's now a fixed length type in
InnoDB, we have to get DATA_POINT_LEN bytes,
which is original prefix length of POINT. */
data_len = key_ptr[data_offset] + 256 * key_ptr[data_offset + 1];
data_field_len =
data_offset + 2 +
(type == DATA_POINT ? DATA_POINT_LEN : field->prefix_len);
data_offset += 2;
/* Now that we know the length, we store the
column value like it would be a fixed char
field */
}
} else if (field->prefix_len > 0) {
/* Looks like MySQL pads unused end bytes in the
prefix with space. Therefore, also in UTF-8, it is ok
to compare with a prefix containing full prefix_len
bytes, and no need to take at most prefix_len / 3
UTF-8 characters from the start.
If the prefix is used as the upper end of a LIKE
'abc%' query, then MySQL pads the end with chars
0xff. TODO: in that case does it any harm to compare
with the full prefix_len bytes. How do characters
0xff in UTF-8 behave? */
data_len = field->prefix_len;
data_field_len = data_offset + data_len;
} else {
data_len = dfield_get_type(dfield)->len;
data_field_len = data_offset + data_len;
}
if ((dtype_get_mysql_type(dfield_get_type(dfield)) ==
DATA_MYSQL_TRUE_VARCHAR) &&
(type != DATA_INT)) {
/* In a MySQL key value format, a true VARCHAR is
always preceded by 2 bytes of a length field.
dfield_get_type(dfield)->len returns the maximum
'payload' len in bytes. That does not include the
2 bytes that tell the actual data length.
We added the check != DATA_INT to make sure we do
not treat MySQL ENUM or SET as a true VARCHAR! */
data_len += 2;
data_field_len += 2;
}
/* Storing may use at most data_len bytes of buf */
if (UNIV_LIKELY(!is_null)) {
buf = row_mysql_store_col_in_innobase_format(
dfield, buf, FALSE, /* MySQL key value format col */
key_ptr + data_offset, data_len, dict_table_is_comp(index->table));
ut_a(buf <= original_buf + buf_len);
}
key_ptr += data_field_len;
if (UNIV_UNLIKELY(key_ptr > key_end)) {
/* The last field in key was not a complete key field
but a prefix of it.
Print a warning about this! HA_READ_PREFIX_LAST does
not currently work in InnoDB with partial-field key
value prefixes. Since MySQL currently uses a padding
trick to calculate LIKE 'abc%' type queries there
should never be partial-field prefixes in searches. */
ib::warn(ER_IB_MSG_1028)
<< "Using a partial-field key prefix in"
" search, index "
<< index->name << " of table " << index->table->name
<< ". Last data field length " << data_field_len
<< " bytes, key ptr now"
" exceeds key end by "
<< (key_ptr - key_end) << " bytes. Key value in the MySQL format:";
ut_print_buf(stderr, original_key_ptr, key_len);
putc('\n', stderr);
if (!is_null) {
ulint len = dfield_get_len(dfield);
dfield_set_len(dfield, len - (ulint)(key_ptr - key_end));
}
ut_ad(0);
}
n_fields++;
field++;
dfield++;
}
ut_a(buf <= original_buf + buf_len);
/* We set the length of tuple to n_fields: we assume that the memory
area allocated for it is big enough (usually bigger than n_fields). */
dtuple_set_n_fields(tuple, n_fields);
}
/** Stores the row id to the prebuilt struct. */
static void row_sel_store_row_id_to_prebuilt(
row_prebuilt_t *prebuilt, /*!< in/out: prebuilt */
const rec_t *index_rec, /*!< in: record */
const dict_index_t *index, /*!< in: index of the record */
const ulint *offsets) /*!< in: rec_get_offsets
(index_rec, index) */
{
const byte *data;
ulint len;
ut_ad(rec_offs_validate(index_rec, index, offsets));
data = rec_get_nth_field(index_rec, offsets,
index->get_sys_col_pos(DATA_ROW_ID), &len);
if (UNIV_UNLIKELY(len != DATA_ROW_ID_LEN)) {
ib::error(ER_IB_MSG_1029)
<< "Row id field is wrong length " << len
<< " in"
" index "
<< index->name << " of table " << index->table->name
<< ", Field number " << index->get_sys_col_pos(DATA_ROW_ID)
<< ", record:";
rec_print_new(stderr, index_rec, offsets);
putc('\n', stderr);
ut_error;
}
ut_memcpy(prebuilt->row_id, data, len);
}
#ifdef UNIV_DEBUG
/** Convert a non-SQL-NULL field from Innobase format to MySQL format. */
#define row_sel_field_store_in_mysql_format(dest, templ, idx, field, src, len, \
sec) \
row_sel_field_store_in_mysql_format_func(dest, templ, idx, field, src, len, \
sec)
#else /* UNIV_DEBUG */
/** Convert a non-SQL-NULL field from Innobase format to MySQL format. */
#define row_sel_field_store_in_mysql_format(dest, templ, idx, field, src, len, \
sec) \
row_sel_field_store_in_mysql_format_func(dest, templ, idx, src, len)
#endif /* UNIV_DEBUG */
/** Stores a non-SQL-NULL field in the MySQL format. The counterpart of this
function is row_mysql_store_col_in_innobase_format() in row0mysql.cc.
@param[in,out] dest buffer where to store; NOTE
that BLOBs are not in themselves stored
here: the caller must allocate and copy
the BLOB into buffer before, and pass
the pointer to the BLOB in 'data'
@param[in] templ MySQL column template. Its following fields
are referenced: type, is_unsigned,
mysql_col_len, mbminlen, mbmaxlen
@param[in] index InnoDB index
@param[in] field_no templ->rec_field_no or templ->clust_rec_field_no
or templ->icp_rec_field_no
@param[in] data data to store
@param[in] len length of the data
@param[in] sec_field secondary index field no if the secondary index
record but the prebuilt template is in
clustered index format and used only for end
range comparison. */
void row_sel_field_store_in_mysql_format_func(byte *dest,
const mysql_row_templ_t *templ,
const dict_index_t *index,
#ifdef UNIV_DEBUG
ulint field_no,
#endif /* UNIV_DEBUG */
const byte *data, ulint len
#ifdef UNIV_DEBUG
,
ulint sec_field
#endif /* UNIV_DEBUG */
) {
byte *ptr;
#ifdef UNIV_DEBUG
const dict_field_t *field =
templ->is_virtual ? NULL : index->get_field(field_no);
bool clust_templ_for_sec = (sec_field != ULINT_UNDEFINED);
#endif /* UNIV_DEBUG */
ulint mysql_col_len =
templ->is_multi_val ? templ->mysql_mvidx_len : templ->mysql_col_len;
ut_ad(rec_field_not_null_not_add_col_def(len));
UNIV_MEM_ASSERT_RW(data, len);
UNIV_MEM_ASSERT_W(dest, templ->mysql_col_len);
UNIV_MEM_INVALID(dest, templ->mysql_col_len);
switch (templ->type) {
const byte *field_end;
byte *pad;
case DATA_INT:
/* Convert integer data from Innobase to a little-endian
format, sign bit restored to normal */
ptr = dest + len;
for (;;) {
ptr--;
*ptr = *data;
if (ptr == dest) {
break;
}
data++;
}
if (!templ->is_unsigned) {
dest[len - 1] = (byte)(dest[len - 1] ^ 128);
}
ut_ad(mysql_col_len == len);
break;
case DATA_VARCHAR:
case DATA_VARMYSQL:
case DATA_BINARY:
field_end = dest + mysql_col_len;
if (templ->mysql_type == DATA_MYSQL_TRUE_VARCHAR) {
/* This is a >= 5.0.3 type true VARCHAR. Store the
length of the data to the first byte or the first
two bytes of dest. */
dest =
row_mysql_store_true_var_len(dest, len, templ->mysql_length_bytes);
/* Copy the actual data. Leave the rest of the
buffer uninitialized. */
memcpy(dest, data, len);
break;
}
/* Copy the actual data */
ut_memcpy(dest, data, len);
/* Pad with trailing spaces. */
pad = dest + len;
ut_ad(templ->mbminlen <= templ->mbmaxlen);
/* We treat some Unicode charset strings specially. */
switch (templ->mbminlen) {
case 4:
/* InnoDB should never have stripped partial
UTF-32 characters. */
ut_a(!(len & 3));
break;
case 2:
/* A space char is two bytes,
0x0020 in UCS2 and UTF-16 */
if (UNIV_UNLIKELY(len & 1)) {
/* A 0x20 has been stripped from the column.
Pad it back. */
if (pad < field_end) {
*pad++ = 0x20;
}
}
}
row_mysql_pad_col(templ->mbminlen, pad, field_end - pad);
break;
case DATA_BLOB:
/* Store a pointer to the BLOB buffer to dest: the BLOB was
already copied to the buffer in row_sel_store_mysql_rec */
row_mysql_store_blob_ref(dest, templ->mysql_col_len, data, len);
break;
case DATA_POINT:
case DATA_VAR_POINT:
case DATA_GEOMETRY:
/* We store all geometry data as BLOB data at server layer. */
row_mysql_store_geometry(dest, templ->mysql_col_len, data, len);
break;
case DATA_MYSQL:
memcpy(dest, data, len);
ut_ad(mysql_col_len >= len);
ut_ad(templ->mbmaxlen >= templ->mbminlen);
/* If field_no equals to templ->icp_rec_field_no,
we are examining a row pointed by "icp_rec_field_no".
There is possibility that icp_rec_field_no refers to
a field in a secondary index while templ->rec_field_no
points to field in a primary index. The length
should still be equal, unless the field pointed
by icp_rec_field_no has a prefix or this is a virtual
column */
ut_ad(templ->is_virtual || templ->mbmaxlen > templ->mbminlen ||
mysql_col_len == len ||
(field_no == templ->icp_rec_field_no && field->prefix_len > 0));
/* The following assertion would fail for old tables
containing UTF-8 ENUM columns due to Bug #9526. */
ut_ad(!templ->mbmaxlen || !(mysql_col_len % templ->mbmaxlen));
/* Length of the record will be less in case of
clust_templ_for_sec is true or if it is fetched
from prefix virtual column in virtual index. */
ut_ad(templ->is_virtual || clust_templ_for_sec ||
len * templ->mbmaxlen >= mysql_col_len ||
(field_no == templ->icp_rec_field_no && field->prefix_len > 0));
ut_ad(templ->is_virtual || !(field->prefix_len % templ->mbmaxlen));
/* Pad with spaces. This undoes the stripping
done in row0mysql.cc, function
row_mysql_store_col_in_innobase_format(). */
if ((templ->mbminlen == 1 && templ->mbmaxlen != 1) ||
(templ->is_virtual && templ->mysql_col_len > len)) {
/* NOTE: This comment is for the second condition:
This probably comes from a prefix virtual index, where no complete
value can be got because the full virtual column can only be
calculated in server layer for now. Since server now assumes the
returned value should always have padding spaces, thus the fixup.
However, a proper and more efficient solution is that server does
not depend on the trailing spaces to check the terminal of the CHAR
string, because at least in this case,server should know it's a prefix
index search and no complete value would be got. */
memset(dest + len, 0x20, mysql_col_len - len);
}
break;
default:
#ifdef UNIV_DEBUG
case DATA_SYS_CHILD:
case DATA_SYS:
/* These column types should never be shipped to MySQL. */
ut_ad(0);
case DATA_CHAR:
case DATA_FIXBINARY:
case DATA_FLOAT:
case DATA_DOUBLE:
case DATA_DECIMAL:
/* Above are the valid column types for MySQL data. */
#endif /* UNIV_DEBUG */
/* If sec_field value is present then mapping of
secondary index records to clustered index template
happens for end range comparison. So length can
vary according to secondary index record length. */
ut_ad((templ->is_virtual && !field) ||
(field && field->prefix_len
? field->prefix_len == len
: clust_templ_for_sec ? 1 : mysql_col_len == len));
memcpy(dest, data, len);
}
}
/** Convert a field from Innobase format to MySQL format. */
#define row_sel_store_mysql_field(m, p, r, i, o, f, t, s, l, bh) \
row_sel_store_mysql_field_func(m, p, r, i, o, f, t, s, l, bh)
// clang-format off
/** Convert a field in the Innobase format to a field in the MySQL format.
@param[out] mysql_rec Record in the MySQL format
@param[in,out] prebuilt Prebuilt struct
@param[in] rec InnoDB record; must be protected by a page latch
@param[in] index Index of rec
@param[in] offsets Array returned by rec_get_offsets()
@param[in] field_no templ->rec_field_no or
templ->clust_rec_field_no
or templ->icp_rec_field_no
or sec field no if clust_templ_for_sec
is true
@param[in] templ Row template
@param[in] sec_field_no Secondary index field no if the secondary index
record but the prebuilt template is in
clustered index format and used only for end
range comparison.
@param[in] lob_undo the LOB undo information.
@param[in,out] blob_heap If not null then use this heap for BLOBs */
// clang-format on
static MY_ATTRIBUTE((warn_unused_result)) bool row_sel_store_mysql_field_func(
byte *mysql_rec, row_prebuilt_t *prebuilt, const rec_t *rec,
const dict_index_t *index, const ulint *offsets, ulint field_no,
const mysql_row_templ_t *templ, ulint sec_field_no,
lob::undo_vers_t *lob_undo, mem_heap_t *blob_heap) {
DBUG_TRACE;
const byte *data;
ulint len;
ulint clust_field_no = 0;
bool clust_templ_for_sec = (sec_field_no != ULINT_UNDEFINED);
ut_ad(templ);
ut_ad(prebuilt->default_rec);
ut_ad(templ >= prebuilt->mysql_template);
ut_ad(templ < &prebuilt->mysql_template[prebuilt->n_template]);
ut_ad(clust_templ_for_sec || field_no == templ->clust_rec_field_no ||
field_no == templ->rec_field_no || field_no == templ->icp_rec_field_no);
ut_ad(rec_offs_validate(
rec, clust_templ_for_sec == true ? prebuilt->index : index, offsets));
/* If sec_field_no is present then extract the data from record
using secondary field no. */
if (clust_templ_for_sec) {
clust_field_no = field_no;
field_no = sec_field_no;
}
if (rec_offs_nth_extern(offsets, field_no)) {
/* Copy an externally stored field to a temporary heap */
ut_a(!prebuilt->trx->has_search_latch);
ut_ad(field_no == templ->clust_rec_field_no);
ut_ad(templ->type != DATA_POINT);
mem_heap_t *heap;
if (DATA_LARGE_MTYPE(templ->type)) {
if (blob_heap != nullptr) {
heap = blob_heap;
} else {
if (prebuilt->blob_heap == nullptr) {
prebuilt->blob_heap = mem_heap_create(UNIV_PAGE_SIZE);
}
heap = prebuilt->blob_heap;
}
} else {
heap = mem_heap_create(UNIV_PAGE_SIZE);
}
/* NOTE: if we are retrieving a big BLOB, we may
already run out of memory in the next call, which
causes an assert */
dict_index_t *clust_index = prebuilt->table->first_index();
const page_size_t page_size = dict_table_page_size(prebuilt->table);
size_t lob_version = 0;
data = lob::btr_rec_copy_externally_stored_field(
prebuilt->trx, clust_index, rec, offsets, page_size, field_no, &len,
&lob_version, dict_index_is_sdi(index), heap);
if (data == nullptr) {
/* The externally stored field was not written
yet. This record should only be seen by
trx_rollback_or_clean_all_recovered() or any
yet. This can happen after optimization which
was done after for Bug#23481444 where we read
last record in the page to find the end range
scan. If we encounter this we just return false
In any other case this row should be only seen
by recv_recovery_rollback_active() or any
TRX_ISO_READ_UNCOMMITTED transactions. */
if (heap != blob_heap && heap != prebuilt->blob_heap) {
mem_heap_free(heap);
}
ut_a((!prebuilt->idx_cond &&
prebuilt->m_mysql_handler->end_range != nullptr) ||
(prebuilt->trx->isolation_level == TRX_ISO_READ_UNCOMMITTED));
return false;
}
if (lob_undo != nullptr) {
ulint local_len;
const byte *field_data =
rec_get_nth_field_instant(rec, offsets, field_no, index, &local_len);
const byte *field_ref =
field_data + local_len - BTR_EXTERN_FIELD_REF_SIZE;
lob::ref_t ref(const_cast<byte *>(field_ref));
lob_undo->apply(clust_index, field_no, const_cast<byte *>(data), len,
lob_version, ref.page_no());
}
ut_a(rec_field_not_null_not_add_col_def(len));
row_sel_field_store_in_mysql_format(mysql_rec + templ->mysql_col_offset,
templ, index, field_no, data, len,
ULINT_UNDEFINED);
if (heap != blob_heap && heap != prebuilt->blob_heap) {
mem_heap_free(heap);
}
} else {
/* Field is stored in the row. */
data = rec_get_nth_field_instant(rec, offsets, field_no, index, &len);
if (len == UNIV_SQL_NULL) {
/* MySQL assumes that the field for an SQL
NULL value is set to the default value. */
ut_ad(templ->mysql_null_bit_mask);
UNIV_MEM_ASSERT_RW(prebuilt->default_rec + templ->mysql_col_offset,
templ->mysql_col_len);
mysql_rec[templ->mysql_null_byte_offset] |=
(byte)templ->mysql_null_bit_mask;
memcpy(mysql_rec + templ->mysql_col_offset,
(const byte *)prebuilt->default_rec + templ->mysql_col_offset,
templ->mysql_col_len);
return true;
}
if (DATA_LARGE_MTYPE(templ->type) || DATA_GEOMETRY_MTYPE(templ->type)) {
/* It is a BLOB field locally stored in the
InnoDB record: we MUST copy its contents to
prebuilt->blob_heap here because
row_sel_field_store_in_mysql_format() stores a
pointer to the data, and the data passed to us
will be invalid as soon as the
mini-transaction is committed and the page
latch on the clustered index page is
released.
For DATA_POINT, it's stored like CHAR in InnoDB,
but it should be a BLOB field in MySQL layer. So we
still treated it as BLOB here. */
mem_heap_t *heap{};
if (blob_heap != nullptr) {
heap = blob_heap;
} else {
if (prebuilt->blob_heap == nullptr) {
prebuilt->blob_heap = mem_heap_create(UNIV_PAGE_SIZE);
}
heap = prebuilt->blob_heap;
}
data = static_cast<byte *>(mem_heap_dup(heap, data, len));
}
/* Reassign the clustered index field no. */
if (clust_templ_for_sec) {
field_no = clust_field_no;
}
row_sel_field_store_in_mysql_format(mysql_rec + templ->mysql_col_offset,
templ, index, field_no, data, len,
sec_field_no);
}
ut_ad(rec_field_not_null_not_add_col_def(len));
if (templ->mysql_null_bit_mask) {
/* It is a nullable column with a non-NULL value */
mysql_rec[templ->mysql_null_byte_offset] &=
~(byte)templ->mysql_null_bit_mask;
}
return true;
}
bool row_sel_store_mysql_rec(byte *mysql_rec, row_prebuilt_t *prebuilt,
const rec_t *rec, const dtuple_t *vrow,
bool rec_clust, const dict_index_t *index,
const ulint *offsets, bool clust_templ_for_sec,
lob::undo_vers_t *lob_undo,
mem_heap_t *blob_heap) {
std::vector<const dict_col_t *> template_col;
DBUG_TRACE;
ut_ad(rec_clust || index == prebuilt->index);
ut_ad(!rec_clust || index->is_clustered());
if (blob_heap != nullptr) {
mem_heap_empty(blob_heap);
} else if (prebuilt->blob_heap != nullptr) {
mem_heap_empty(prebuilt->blob_heap);
}
if (clust_templ_for_sec) {
/* Store all clustered index column of secondary index record. */
for (ulint i = 0; i < dict_index_get_n_fields(prebuilt->index); i++) {
auto sec_field = dict_index_get_nth_field_pos(index, prebuilt->index, i);
if (sec_field == ULINT_UNDEFINED) {
template_col.push_back(nullptr);
continue;
}
const auto field = index->get_field(sec_field);
const auto col = field->col;
template_col.push_back(col);
}
}
for (ulint i = 0; i < prebuilt->n_template; i++) {
const auto templ = &prebuilt->mysql_template[i];
if (templ->is_virtual && index->is_clustered()) {
/* Skip virtual columns if it is not a covered
search or virtual key read is not requested. */
if ((prebuilt->index != nullptr &&
!dict_index_has_virtual(prebuilt->index)) ||
(!prebuilt->read_just_key && !prebuilt->m_read_virtual_key) ||
!rec_clust) {
continue;
}
dict_v_col_t *col;
col = dict_table_get_nth_v_col(index->table, templ->clust_rec_field_no);
ut_ad(vrow);
const auto dfield = dtuple_get_nth_v_field(vrow, col->v_pos);
/* If this is a partitioned table, it might request
InnoDB to fill out virtual column data for serach
index key values while other non key columns are also
getting selected. The non-key virtual columns may
not be materialized and we should skip them. */
if (dfield_get_type(dfield)->mtype == DATA_MISSING) {
ut_ad(prebuilt->m_read_virtual_key);
/* If it is part of index key the data should
have been materialized. */
ut_ad(prebuilt->index->get_col_pos(col->v_pos, false, true) ==
ULINT_UNDEFINED);
continue;
}
if (dfield->len == UNIV_SQL_NULL) {
mysql_rec[templ->mysql_null_byte_offset] |=
(byte)templ->mysql_null_bit_mask;
memcpy(mysql_rec + templ->mysql_col_offset,
(const byte *)prebuilt->default_rec + templ->mysql_col_offset,
templ->mysql_col_len);
} else {
row_sel_field_store_in_mysql_format(
mysql_rec + templ->mysql_col_offset, templ, index,
templ->clust_rec_field_no, (const byte *)dfield->data, dfield->len,
ULINT_UNDEFINED);
if (templ->mysql_null_bit_mask) {
mysql_rec[templ->mysql_null_byte_offset] &=
~(byte)templ->mysql_null_bit_mask;
}
}
continue;
}
ulint field_no =
rec_clust ? templ->clust_rec_field_no : templ->rec_field_no;
ulint sec_field_no = ULINT_UNDEFINED;
/* We should never deliver column prefixes to MySQL,
except for evaluating innobase_index_cond() or
row_search_end_range_check(). */
ut_ad(index->get_field(field_no)->prefix_len == 0);
if (clust_templ_for_sec) {
std::vector<const dict_col_t *>::iterator it;
const dict_field_t *field = index->get_field(field_no);
const dict_col_t *col = field->col;
it = std::find(template_col.begin(), template_col.end(), col);
if (it == template_col.end()) {
continue;
}
ut_ad(templ->rec_field_no == templ->clust_rec_field_no);
sec_field_no = it - template_col.begin();
}
if (!row_sel_store_mysql_field(mysql_rec, prebuilt, rec, index, offsets,
field_no, templ, sec_field_no, lob_undo,
blob_heap)) {
return false;
}
}
/* FIXME: We only need to read the doc_id if an FTS indexed
column is being updated.
NOTE, the record can be cluster or secondary index record.
if secondary index is used then FTS_DOC_ID column should be part
of this index. */
if (dict_table_has_fts_index(prebuilt->table)) {
if ((index->is_clustered() && !clust_templ_for_sec) ||
prebuilt->fts_doc_id_in_read_set) {
prebuilt->fts_doc_id =
fts_get_doc_id_from_rec(prebuilt->table, rec, index, NULL);
}
}
return true;
}
/** Builds a previous version of a clustered index record for a consistent read
@param[in] read_view read view
@param[in] clust_index clustered index
@param[in] prebuilt prebuilt struct
@param[in] rec record in clustered index
@param[in,out] offsets offsets returned by
rec_get_offsets(rec, clust_index)
@param[in,out] offset_heap memory heap from which the offsets are
allocated
@param[out] old_vers old version, or NULL if the record does not
exist in the view: i.e., it was freshly
inserted afterwards
@param[out] vrow dtuple to hold old virtual column data
@param[in] mtr the mini transaction context.
@param[in,out] lob_undo Undo information for BLOBs.
@return DB_SUCCESS or error code */
static MY_ATTRIBUTE((warn_unused_result)) dberr_t
row_sel_build_prev_vers_for_mysql(lizard::Vision *vision,
dict_index_t *clust_index,
row_prebuilt_t *prebuilt,
const rec_t *rec, ulint **offsets,
mem_heap_t **offset_heap,
rec_t **old_vers, const dtuple_t **vrow,
mtr_t *mtr, lob::undo_vers_t *lob_undo) {
DBUG_TRACE;
dberr_t err;
if (prebuilt->old_vers_heap) {
mem_heap_empty(prebuilt->old_vers_heap);
} else {
prebuilt->old_vers_heap = mem_heap_create(200);
}
err = row_vers_build_for_consistent_read(
rec, mtr, clust_index, offsets, vision, offset_heap,
prebuilt->old_vers_heap, old_vers, vrow, lob_undo);
return err;
}
/** Helper class to cache clust_rec and old_ver */
class Row_sel_get_clust_rec_for_mysql {
const rec_t *cached_clust_rec;
rec_t *cached_old_vers;
public:
/** Constructor */
Row_sel_get_clust_rec_for_mysql()
: cached_clust_rec(nullptr), cached_old_vers(nullptr) {}
/** Retrieve the clustered index record corresponding to a record in a
non-clustered index. Does the necessary locking.
@param[in] prebuilt prebuilt struct in the handle
@param[in] sec_index secondary index where rec resides
@param[in] rec record in a non-clustered index
@param[in] thr query thread
@param[out] out_rec clustered record or an old version of it,
NULL if the old version did not exist in the
read view, i.e., it was a fresh inserted version
@param[in,out] offsets in: offsets returned by
rec_get_offsets(rec, sec_index);
out: offsets returned by
rec_get_offsets(out_rec, clust_index)
@param[in,out] offset_heap memory heap from which the offsets are allocated
@param[out] vrow virtual column to fill
@param[in] mtr mtr used to get access to the non-clustered record;
the same mtr is used to access the clustered index
@param[in] lob_undo the LOB undo information.
@return DB_SUCCESS, DB_SUCCESS_LOCKED_REC, or error code */
dberr_t operator()(row_prebuilt_t *prebuilt, dict_index_t *sec_index,
const rec_t *rec, que_thr_t *thr, const rec_t **out_rec,
ulint **offsets, mem_heap_t **offset_heap,
const dtuple_t **vrow, mtr_t *mtr,
lob::undo_vers_t *lob_undo);
};
/** Retrieve the clustered index record corresponding to a record in a
non-clustered index. Does the necessary locking.
@return DB_SUCCESS, DB_SUCCESS_LOCKED_REC, or error code */
MY_ATTRIBUTE((warn_unused_result))
dberr_t Row_sel_get_clust_rec_for_mysql::operator()(
row_prebuilt_t *prebuilt, dict_index_t *sec_index, const rec_t *rec,
que_thr_t *thr, const rec_t **out_rec, ulint **offsets,
mem_heap_t **offset_heap, const dtuple_t **vrow, mtr_t *mtr,
lob::undo_vers_t *lob_undo) {
DBUG_TRACE;
dict_index_t *clust_index;
const rec_t *clust_rec;
rec_t *old_vers;
dberr_t err;
trx_t *trx;
*out_rec = NULL;
trx = thr_get_trx(thr);
row_build_row_ref_in_tuple(prebuilt->clust_ref, rec, sec_index, *offsets,
trx);
clust_index = sec_index->table->first_index();
btr_pcur_open_with_no_init(clust_index, prebuilt->clust_ref, PAGE_CUR_LE,
BTR_SEARCH_LEAF, prebuilt->clust_pcur, 0, mtr);
clust_rec = btr_pcur_get_rec(prebuilt->clust_pcur);
prebuilt->clust_pcur->m_trx_if_known = trx;
/* Note: only if the search ends up on a non-infimum record is the
low_match value the real match to the search tuple */
if (!page_rec_is_user_rec(clust_rec) ||
btr_pcur_get_low_match(prebuilt->clust_pcur) <
dict_index_get_n_unique(clust_index)) {
btr_cur_t *btr_cur = btr_pcur_get_btr_cur(prebuilt->pcur);
/* If this is a spatial index scan, and we are reading
from a shadow buffer, the record could be already
deleted (due to rollback etc.). So get the original
page and verify that */
if (dict_index_is_spatial(sec_index) && btr_cur->rtr_info->matches &&
(page_align(rec) == btr_cur->rtr_info->matches->block.frame ||
rec != btr_pcur_get_rec(prebuilt->pcur))) {
#ifdef UNIV_DEBUG
rtr_info_t *rtr_info = btr_cur->rtr_info;
mutex_enter(&rtr_info->matches->rtr_match_mutex);
/* The page could be deallocated (by rollback etc.) */
if (!rtr_info->matches->valid) {
mutex_exit(&rtr_info->matches->rtr_match_mutex);
clust_rec = NULL;
err = DB_SUCCESS;
goto func_exit;
}
mutex_exit(&rtr_info->matches->rtr_match_mutex);
if (rec_get_deleted_flag(rec, dict_table_is_comp(sec_index->table)) &&
prebuilt->select_lock_type == LOCK_NONE) {
clust_rec = NULL;
err = DB_SUCCESS;
goto func_exit;
}
if (rec != btr_pcur_get_rec(prebuilt->pcur)) {
clust_rec = NULL;
err = DB_SUCCESS;
goto func_exit;
}
page_no_t page_no = page_get_page_no(btr_pcur_get_page(prebuilt->pcur));
page_id_t page_id(dict_index_get_space(sec_index), page_no);
buf_block_t *block = buf_page_get_gen(
page_id, dict_table_page_size(sec_index->table), RW_NO_LATCH, NULL,
Page_fetch::NORMAL, __FILE__, __LINE__, mtr);
mem_heap_t *heap = mem_heap_create(256);
dtuple_t *tuple =
dict_index_build_data_tuple(sec_index, const_cast<rec_t *>(rec),
dict_index_get_n_fields(sec_index), heap);
;
page_cur_t page_cursor;
ulint low_match =
page_cur_search(block, sec_index, tuple, PAGE_CUR_LE, &page_cursor);
ut_ad(low_match < dtuple_get_n_fields_cmp(tuple));
mem_heap_free(heap);
clust_rec = NULL;
err = DB_SUCCESS;
goto func_exit;
#endif /* UNIV_DEBUG */
} else if (!rec_get_deleted_flag(rec,
dict_table_is_comp(sec_index->table)) ||
prebuilt->select_lock_type != LOCK_NONE) {
/* In a rare case it is possible that no clust
rec is found for a delete-marked secondary index
record: if in row0umod.cc in
row_undo_mod_remove_clust_low() we have already removed
the clust rec, while purge is still cleaning and
removing secondary index records associated with
earlier versions of the clustered index record.
In that case we know that the clustered index
record did not exist in the read view of trx. */
ib::error(ER_IB_MSG_1030)
<< "Clustered record for sec rec not found"
" index "
<< sec_index->name << " of table " << sec_index->table->name;
fputs("InnoDB: sec index record ", stderr);
rec_print(stderr, rec, sec_index);
fputs(
"\n"
"InnoDB: clust index record ",
stderr);
rec_print(stderr, clust_rec, clust_index);
putc('\n', stderr);
trx_print(stderr, trx, 600);
fputs(
"\n"
"InnoDB: Submit a detailed bug report"
" to http://bugs.mysql.com\n",
stderr);
ut_ad(0);
}
clust_rec = NULL;
err = DB_SUCCESS;
goto func_exit;
}
*offsets = rec_get_offsets(clust_rec, clust_index, *offsets, ULINT_UNDEFINED,
offset_heap);
if (prebuilt->select_lock_type != LOCK_NONE) {
/* Try to place a lock on the index record; we are searching
the clust rec with a unique condition, hence
we set a LOCK_REC_NOT_GAP type lock */
err = lock_clust_rec_read_check_and_lock(
lock_duration_t::REGULAR, btr_pcur_get_block(prebuilt->clust_pcur),
clust_rec, clust_index, *offsets, prebuilt->select_mode,
static_cast<lock_mode>(prebuilt->select_lock_type), LOCK_REC_NOT_GAP,
thr);
switch (err) {
case DB_SUCCESS:
case DB_SUCCESS_LOCKED_REC:
break;
default:
goto err_exit;
}
} else {
/* This is a non-locking consistent read: if necessary, fetch
a previous version of the record */
old_vers = NULL;
/* If the isolation level allows reading of uncommitted data,
then we never look for an earlier version */
if (trx_get_vision(trx)->is_asof_gcn()) {
dberr_t gp_error = DB_SUCCESS;
bool see = lizard::gp_clust_rec_cons_read_sees(
trx, clust_rec, clust_index, *offsets, prebuilt->clust_pcur,
trx_get_vision(trx), &gp_error);
if (gp_error != DB_SUCCESS) {
err = gp_error;
goto err_exit;
} else {
if (!see) {
if (clust_rec != cached_clust_rec) {
/* The following call returns 'offsets' associated with 'old_vers'
*/
err = row_sel_build_prev_vers_for_mysql(
&trx->vision, clust_index, prebuilt, clust_rec, offsets,
offset_heap, &old_vers, vrow, mtr, lob_undo);
if (err != DB_SUCCESS) {
goto err_exit;
}
cached_clust_rec = clust_rec;
cached_old_vers = old_vers;
} else {
err = DB_SUCCESS;
old_vers = cached_old_vers;
if (old_vers != nullptr) {
DBUG_EXECUTE_IF("innodb_cached_old_vers_offsets", {
rec_offs_make_valid(old_vers, clust_index, *offsets);
if (!lob::rec_check_lobref_space_id(clust_index, old_vers,
*offsets)) {
DBUG_SUICIDE();
}
});
/* The offsets need not be same for the latest version of
clust_rec and its old version old_vers. Re-calculate the offsets
for old_vers. */
*offsets = rec_get_offsets(old_vers, clust_index, *offsets,
ULINT_UNDEFINED, offset_heap);
ut_ad(lob::rec_check_lobref_space_id(clust_index, old_vers,
*offsets));
}
}
if (old_vers == NULL) {
goto err_exit;
}
clust_rec = old_vers;
}
}
} else if (trx->isolation_level > TRX_ISO_READ_UNCOMMITTED &&
!lock_clust_rec_cons_read_sees(clust_rec, clust_index, *offsets,
prebuilt->clust_pcur,
trx_get_vision(trx))) {
if (clust_rec != cached_clust_rec) {
/* The following call returns 'offsets' associated with 'old_vers' */
err = row_sel_build_prev_vers_for_mysql(
&trx->vision, clust_index, prebuilt, clust_rec, offsets,
offset_heap, &old_vers, vrow, mtr, lob_undo);
if (err != DB_SUCCESS) {
goto err_exit;
}
cached_clust_rec = clust_rec;
cached_old_vers = old_vers;
} else {
err = DB_SUCCESS;
old_vers = cached_old_vers;
if (old_vers != nullptr) {
DBUG_EXECUTE_IF("innodb_cached_old_vers_offsets", {
rec_offs_make_valid(old_vers, clust_index, *offsets);
if (!lob::rec_check_lobref_space_id(clust_index, old_vers,
*offsets)) {
DBUG_SUICIDE();
}
});
/* The offsets need not be same for the latest version of
clust_rec and its old version old_vers. Re-calculate the offsets
for old_vers. */
*offsets = rec_get_offsets(old_vers, clust_index, *offsets,
ULINT_UNDEFINED, offset_heap);
ut_ad(
lob::rec_check_lobref_space_id(clust_index, old_vers, *offsets));
}
}
if (old_vers == NULL) {
goto err_exit;
}
clust_rec = old_vers;
}
/* If we had to go to an earlier version of row or the
secondary index record is delete marked, then it may be that
the secondary index record corresponding to clust_rec
(or old_vers) is not rec; in that case we must ignore
such row because in our snapshot rec would not have existed.
Remember that from rec we cannot see directly which transaction
id corresponds to it: we have to go to the clustered index
record. A query where we want to fetch all rows where
the secondary index value is in some interval would return
a wrong result if we would not drop rows which we come to
visit through secondary index records that would not really
exist in our snapshot. */
/* And for spatial index, since the rec is from shadow buffer,
so we need to check if it's exactly match the clust_rec. */
if (clust_rec &&
(old_vers || trx->isolation_level <= TRX_ISO_READ_UNCOMMITTED ||
dict_index_is_spatial(sec_index) ||
rec_get_deleted_flag(rec, dict_table_is_comp(sec_index->table)))) {
bool rec_equal;
err = row_sel_sec_rec_is_for_clust_rec(rec, sec_index, clust_rec,
clust_index, thr, rec_equal);
if (err != DB_SUCCESS) {
goto err_exit;
} else if (!rec_equal) {
clust_rec = NULL;
}
}
err = DB_SUCCESS;
}
func_exit:
*out_rec = clust_rec;
/* Store the current position if select_lock_type is not
LOCK_NONE or if we are scanning using InnoDB APIs */
if (prebuilt->select_lock_type != LOCK_NONE || prebuilt->innodb_api) {
/* We may use the cursor in update or in unlock_row():
store its position */
btr_pcur_store_position(prebuilt->clust_pcur, mtr);
}
err_exit:
return err;
}
/** Restores cursor position after it has been stored. We have to take into
account that the record cursor was positioned on may have been deleted.
Then we may have to move the cursor one step up or down.
@return true if we may need to process the record the cursor is now
positioned on (i.e. we should not go to the next record yet) */
static ibool sel_restore_position_for_mysql(
ibool *same_user_rec, /*!< out: TRUE if we were able to restore
the cursor on a user record with the
same ordering prefix in in the
B-tree index */
ulint latch_mode, /*!< in: latch mode wished in
restoration */
btr_pcur_t *pcur, /*!< in: cursor whose position
has been stored */
row_prebuilt_t *prebuilt, /*< in: for sampling */
ibool moves_up, /*!< in: TRUE if the cursor moves up
in the index */
mtr_t *mtr) /*!< in: mtr; CAUTION: may commit
mtr temporarily! */
{
ibool success;
ut_ad(!prebuilt || prebuilt->pcur == pcur);
if (prebuilt && prebuilt->sample->enabled)
success = btr_sample_pcur_restore(prebuilt->sample, mtr);
else
success = btr_pcur_restore_position(latch_mode, pcur, mtr);
*same_user_rec = success;
ut_ad(!success || pcur->m_rel_pos == BTR_PCUR_ON);
#ifdef UNIV_DEBUG
if (pcur->m_pos_state == BTR_PCUR_IS_POSITIONED_OPTIMISTIC) {
ut_ad(pcur->m_rel_pos == BTR_PCUR_BEFORE ||
pcur->m_rel_pos == BTR_PCUR_AFTER);
} else {
ut_ad(pcur->m_pos_state == BTR_PCUR_IS_POSITIONED);
ut_ad((pcur->m_rel_pos == BTR_PCUR_ON) == btr_pcur_is_on_user_rec(pcur));
}
#endif /* UNIV_DEBUG */
/* The position may need be adjusted for rel_pos and moves_up. */
switch (pcur->m_rel_pos) {
case BTR_PCUR_UNSET:
ut_ad(0);
return (TRUE);
case BTR_PCUR_ON:
if (!success && moves_up) {
next:
btr_pcur_move_to_next(pcur, mtr);
return (TRUE);
}
return (!success);
case BTR_PCUR_AFTER_LAST_IN_TREE:
case BTR_PCUR_BEFORE_FIRST_IN_TREE:
return (TRUE);
case BTR_PCUR_AFTER:
/* positioned to record after pcur->old_rec. */
pcur->m_pos_state = BTR_PCUR_IS_POSITIONED;
prev:
if (btr_pcur_is_on_user_rec(pcur) && !moves_up) {
btr_pcur_move_to_prev(pcur, mtr);
}
return (TRUE);
case BTR_PCUR_BEFORE:
/* For non optimistic restoration:
The position is now set to the record before pcur->old_rec.
For optimistic restoration:
The position also needs to take the previous search_mode into
consideration. */
switch (pcur->m_pos_state) {
case BTR_PCUR_IS_POSITIONED_OPTIMISTIC:
pcur->m_pos_state = BTR_PCUR_IS_POSITIONED;
if (pcur->m_search_mode == PAGE_CUR_GE) {
/* Positioned during Greater or Equal search
with BTR_PCUR_BEFORE. Optimistic restore to
the same record. If scanning for lower then
we must move to previous record.
This can happen with:
HANDLER READ idx a = (const);
HANDLER READ idx PREV; */
goto prev;
}
return (TRUE);
case BTR_PCUR_IS_POSITIONED:
if (moves_up && btr_pcur_is_on_user_rec(pcur)) {
goto next;
}
return (TRUE);
case BTR_PCUR_WAS_POSITIONED:
case BTR_PCUR_NOT_POSITIONED:
break;
}
}
ut_ad(0);
return (TRUE);
}
/** Copies a cached field for MySQL from the fetch cache. */
static void row_sel_copy_cached_field_for_mysql(
byte *buf, /*!< in/out: row buffer */
const byte *cache, /*!< in: cached row */
const mysql_row_templ_t *templ) /*!< in: column template */
{
ulint len;
buf += templ->mysql_col_offset;
cache += templ->mysql_col_offset;
UNIV_MEM_ASSERT_W(buf, templ->mysql_col_len);
if (templ->mysql_type == DATA_MYSQL_TRUE_VARCHAR &&
(templ->type != DATA_INT)) {
/* Check for != DATA_INT to make sure we do
not treat MySQL ENUM or SET as a true VARCHAR!
Find the actual length of the true VARCHAR field. */
row_mysql_read_true_varchar(&len, cache, templ->mysql_length_bytes);
len += templ->mysql_length_bytes;
UNIV_MEM_INVALID(buf, templ->mysql_col_len);
} else {
len = templ->mysql_col_len;
}
ut_memcpy(buf, cache, len);
}
/** Copy used fields from cached row.
Copy cache record field by field, don't touch fields that
are not covered by current key.
@param[out] buf Where to copy the MySQL row.
@param[in] cached_rec What to copy (in MySQL row format).
@param[in] prebuilt prebuilt struct. */
void row_sel_copy_cached_fields_for_mysql(byte *buf, const byte *cached_rec,
row_prebuilt_t *prebuilt) {
const mysql_row_templ_t *templ;
ulint i;
for (i = 0; i < prebuilt->n_template; i++) {
templ = prebuilt->mysql_template + i;
/* Skip virtual columns */
if (templ->is_virtual) {
continue;
}
row_sel_copy_cached_field_for_mysql(buf, cached_rec, templ);
/* Copy NULL bit of the current field from cached_rec
to buf */
if (templ->mysql_null_bit_mask) {
buf[templ->mysql_null_byte_offset] ^=
(buf[templ->mysql_null_byte_offset] ^
cached_rec[templ->mysql_null_byte_offset]) &
(byte)templ->mysql_null_bit_mask;
}
}
}
/** Get the record buffer provided by the server, if there is one.
@param prebuilt prebuilt struct
@return the record buffer, or nullptr if none was provided */
static Record_buffer *row_sel_get_record_buffer(
const row_prebuilt_t *prebuilt) {
if (prebuilt->m_mysql_handler == nullptr) {
return nullptr;
}
return prebuilt->m_mysql_handler->ha_get_record_buffer();
}
/** Pops a cached row for MySQL from the fetch cache. */
UNIV_INLINE
void row_sel_dequeue_cached_row_for_mysql(
byte *buf, /*!< in/out: buffer where to copy the
row */
row_prebuilt_t *prebuilt) /*!< in: prebuilt struct */
{
ulint i;
const mysql_row_templ_t *templ;
const byte *cached_rec;
ut_ad(prebuilt->n_fetch_cached > 0);
ut_ad(prebuilt->mysql_prefix_len <= prebuilt->mysql_row_len);
UNIV_MEM_ASSERT_W(buf, prebuilt->mysql_row_len);
/* The row is cached in the server-provided buffer, if there
is one. If not, get it from our own prefetch cache.*/
const auto record_buffer = row_sel_get_record_buffer(prebuilt);
cached_rec = record_buffer
? record_buffer->record(prebuilt->fetch_cache_first)
: prebuilt->fetch_cache[prebuilt->fetch_cache_first];
if (UNIV_UNLIKELY(prebuilt->keep_other_fields_on_keyread)) {
row_sel_copy_cached_fields_for_mysql(buf, cached_rec, prebuilt);
} else if (prebuilt->mysql_prefix_len > 63) {
/* The record is long. Copy it field by field, in case
there are some long VARCHAR column of which only a
small length is being used. */
UNIV_MEM_INVALID(buf, prebuilt->mysql_prefix_len);
/* First copy the NULL bits. */
ut_memcpy(buf, cached_rec, prebuilt->null_bitmap_len);
/* Then copy the requested fields. */
for (i = 0; i < prebuilt->n_template; i++) {
templ = prebuilt->mysql_template + i;
/* Skip virtual columns */
if (templ->is_virtual && !(dict_index_has_virtual(prebuilt->index) &&
prebuilt->read_just_key)) {
continue;
}
row_sel_copy_cached_field_for_mysql(buf, cached_rec, templ);
}
} else {
ut_memcpy(buf, cached_rec, prebuilt->mysql_prefix_len);
}
prebuilt->n_fetch_cached--;
prebuilt->fetch_cache_first++;
if (prebuilt->n_fetch_cached == 0) {
/* All the prefetched records have been returned.
Rewind so that we can insert records at the beginning
of the prefetch cache or record buffer. */
prebuilt->fetch_cache_first = 0;
if (record_buffer != nullptr) {
record_buffer->clear();
}
}
}
/** Initialise the prefetch cache. */
UNIV_INLINE
void row_sel_prefetch_cache_init(
row_prebuilt_t *prebuilt) /*!< in/out: prebuilt struct */
{
ulint i;
ulint sz;
byte *ptr;
/* We use our own prefetch cache only if the server didn't
provide one. */
ut_ad(row_sel_get_record_buffer(prebuilt) == nullptr);
/* Reserve space for the magic number. */
sz = UT_ARR_SIZE(prebuilt->fetch_cache) * (prebuilt->mysql_row_len + 8);
ptr = static_cast<byte *>(ut_malloc_nokey(sz));
for (i = 0; i < UT_ARR_SIZE(prebuilt->fetch_cache); i++) {
/* A user has reported memory corruption in these
buffers in Linux. Put magic numbers there to help
to track a possible bug. */
mach_write_to_4(ptr, ROW_PREBUILT_FETCH_MAGIC_N);
ptr += 4;
prebuilt->fetch_cache[i] = ptr;
ptr += prebuilt->mysql_row_len;
mach_write_to_4(ptr, ROW_PREBUILT_FETCH_MAGIC_N);
ptr += 4;
}
}
/** Get the last fetch cache buffer from the queue.
@return pointer to buffer. */
UNIV_INLINE
byte *row_sel_fetch_last_buf(
row_prebuilt_t *prebuilt) /*!< in/out: prebuilt struct */
{
const auto record_buffer = row_sel_get_record_buffer(prebuilt);
ut_ad(!prebuilt->templ_contains_blob);
if (record_buffer == nullptr) {
ut_ad(prebuilt->n_fetch_cached < MYSQL_FETCH_CACHE_SIZE);
} else {
ut_ad(prebuilt->mysql_prefix_len <= record_buffer->record_size());
ut_ad(record_buffer->records() == prebuilt->n_fetch_cached);
}
if (record_buffer == nullptr && prebuilt->fetch_cache[0] == nullptr) {
/* Allocate memory for the fetch cache */
ut_ad(prebuilt->n_fetch_cached == 0);
row_sel_prefetch_cache_init(prebuilt);
}
/* Use the server-provided buffer if there is one. Otherwise,
use our own prefetch buffer. */
byte *buf = record_buffer ? record_buffer->add_record()
: prebuilt->fetch_cache[prebuilt->n_fetch_cached];
ut_ad(prebuilt->fetch_cache_first == 0);
UNIV_MEM_INVALID(buf, record_buffer ? record_buffer->record_size()
: prebuilt->mysql_row_len);
return (buf);
}
/** Pushes a row for MySQL to the fetch cache. */
UNIV_INLINE
void row_sel_enqueue_cache_row_for_mysql(
byte *mysql_rec, /*!< in/out: MySQL record */
row_prebuilt_t *prebuilt) /*!< in/out: prebuilt struct */
{
/* For non ICP code path the row should already exist in the
next fetch cache slot. */
if (prebuilt->idx_cond) {
byte *dest = row_sel_fetch_last_buf(prebuilt);
ut_memcpy(dest, mysql_rec, prebuilt->mysql_prefix_len);
}
++prebuilt->n_fetch_cached;
}
/** Tries to do a shortcut to fetch a clustered index record with a unique key,
using the hash index if possible (not always). We assume that the search
mode is PAGE_CUR_GE, it is a consistent read, there is a read view in trx,
btr search latch has been locked in S-mode if AHI is enabled.
@return SEL_FOUND, SEL_EXHAUSTED, SEL_RETRY */
static ulint row_sel_try_search_shortcut_for_mysql(
const rec_t **out_rec, /*!< out: record if found */
row_prebuilt_t *prebuilt, /*!< in: prebuilt struct */
ulint **offsets, /*!< in/out: for rec_get_offsets(*out_rec) */
mem_heap_t **heap, /*!< in/out: heap for rec_get_offsets() */
mtr_t *mtr) /*!< in: started mtr */
{
dict_index_t *index = prebuilt->index;
const dtuple_t *search_tuple = prebuilt->search_tuple;
btr_pcur_t *pcur = prebuilt->pcur;
trx_t *trx = prebuilt->trx;
const rec_t *rec;
ut_ad(index->is_clustered());
ut_ad(!prebuilt->templ_contains_blob);
btr_pcur_open_with_no_init(index, search_tuple, PAGE_CUR_GE, BTR_SEARCH_LEAF,
pcur, (trx->has_search_latch) ? RW_S_LATCH : 0,
mtr);
rec = btr_pcur_get_rec(pcur);
if (!page_rec_is_user_rec(rec)) {
return (SEL_RETRY);
}
/* As the cursor is now placed on a user record after a search with
the mode PAGE_CUR_GE, the up_match field in the cursor tells how many
fields in the user record matched to the search tuple */
if (btr_pcur_get_up_match(pcur) < dtuple_get_n_fields(search_tuple)) {
return (SEL_EXHAUSTED);
}
/* This is a non-locking consistent read: if necessary, fetch
a previous version of the record */
*offsets = rec_get_offsets(rec, index, *offsets, ULINT_UNDEFINED, heap);
if (!lock_clust_rec_cons_read_sees(rec, index, *offsets, pcur,
trx_get_vision(trx))) {
return (SEL_RETRY);
}
if (rec_get_deleted_flag(rec, dict_table_is_comp(index->table))) {
return (SEL_EXHAUSTED);
}
*out_rec = rec;
return (SEL_FOUND);
}
/** Check a pushed-down index condition.
@return ICP_NO_MATCH, ICP_MATCH, or ICP_OUT_OF_RANGE */
static ICP_RESULT row_search_idx_cond_check(
byte *mysql_rec, /*!< out: record
in MySQL format (invalid unless
prebuilt->idx_cond == true and
we return ICP_MATCH) */
row_prebuilt_t *prebuilt, /*!< in/out: prebuilt struct
for the table handle */
const rec_t *rec, /*!< in: InnoDB record */
const ulint *offsets) /*!< in: rec_get_offsets() */
{
ICP_RESULT result;
ulint i;
ut_ad(rec_offs_validate(rec, prebuilt->index, offsets));
if (!prebuilt->idx_cond) {
return (ICP_MATCH);
}
MONITOR_INC(MONITOR_ICP_ATTEMPTS);
/* Convert to MySQL format those fields that are needed for
evaluating the index condition. */
if (prebuilt->blob_heap != nullptr) {
mem_heap_empty(prebuilt->blob_heap);
}
for (i = 0; i < prebuilt->idx_cond_n_cols; i++) {
const mysql_row_templ_t *templ = &prebuilt->mysql_template[i];
/* Skip virtual columns */
if (templ->is_virtual) {
continue;
}
if (!row_sel_store_mysql_field(mysql_rec, prebuilt, rec, prebuilt->index,
offsets, templ->icp_rec_field_no, templ,
ULINT_UNDEFINED, nullptr, nullptr)) {
return (ICP_NO_MATCH);
}
}
/* We assume that the index conditions on
case-insensitive columns are case-insensitive. The
case of such columns may be wrong in a secondary
index, if the case of the column has been updated in
the past, or a record has been deleted and a record
inserted in a different case. */
result = innobase_index_cond(prebuilt->m_mysql_handler);
switch (result) {
case ICP_MATCH:
/* Convert the remaining fields to MySQL format.
If this is a secondary index record, we must defer
this until we have fetched the clustered index record. */
if (!prebuilt->need_to_access_clustered ||
prebuilt->index->is_clustered()) {
if (!row_sel_store_mysql_rec(mysql_rec, prebuilt, rec, NULL, FALSE,
prebuilt->index, offsets, false, nullptr,
nullptr)) {
ut_ad(prebuilt->index->is_clustered());
return (ICP_NO_MATCH);
}
}
MONITOR_INC(MONITOR_ICP_MATCH);
return (result);
case ICP_NO_MATCH:
MONITOR_INC(MONITOR_ICP_NO_MATCH);
return (result);
case ICP_OUT_OF_RANGE:
MONITOR_INC(MONITOR_ICP_OUT_OF_RANGE);
const auto record_buffer = row_sel_get_record_buffer(prebuilt);
if (record_buffer) {
record_buffer->set_out_of_range(true);
}
return (result);
}
ut_error;
return (result);
}
/** Check the pushed-down end-range condition to avoid extra traversal
if records are not with in view and also to avoid prefetching too
many records into the record buffer.
@param[in] mysql_rec record in MySQL format
@param[in] rec InnoDB record
@param[in] prebuilt prebuilt struct
@param[in] clust_templ_for_sec true if \a rec belongs to the secondary
index but the \a prebuilt template is in
clustered index format
@param[in] offsets information about column offsets in the
secondary index, if virtual columns need
to be copied into \a mysql_rec
@param[in,out] record_buffer the record buffer we are reading into,
or \c nullptr if there is no buffer
@retval true if the row in \a mysql_rec is out of range
@retval false if the row in \a mysql_rec is in range */
static bool row_search_end_range_check(byte *mysql_rec, const rec_t *rec,
row_prebuilt_t *prebuilt,
bool clust_templ_for_sec,
const ulint *offsets,
Record_buffer *record_buffer) {
const auto handler = prebuilt->m_mysql_handler;
ut_ad(handler->end_range != nullptr);
/* When reading from non-covering secondary indexes, mysql_rec won't
have the values of virtual columns until the handler has called
update_generated_read_fields(). If the end-range condition refers to a
virtual column, we may have to copy its value from the secondary index
before evaluating the condition. */
if (clust_templ_for_sec && handler->m_virt_gcol_in_end_range) {
ut_ad(offsets != nullptr);
for (ulint i = 0; i < prebuilt->n_template; ++i) {
const auto &templ = prebuilt->mysql_template[i];
if (templ.is_virtual && templ.icp_rec_field_no != ULINT_UNDEFINED &&
!row_sel_store_mysql_field(mysql_rec, prebuilt, rec, prebuilt->index,
offsets, templ.icp_rec_field_no, &templ,
ULINT_UNDEFINED, nullptr, nullptr)) {
return (false);
}
}
}
if (handler->compare_key_in_buffer(mysql_rec) > 0) {
if (record_buffer != NULL) {
record_buffer->set_out_of_range(true);
}
return (true);
}
return (false);
}
/** Traverse to next/previous record.
@param[in] moves_up if true, move to next record else previous
@param[in] match_mode 0 or ROW_SEL_EXACT or ROW_SEL_EXACT_PREFIX
@param[in,out] pcur cursor to record
@param[in] mtr mini transaction
@return DB_SUCCESS or error code */
static dberr_t row_search_traverse(bool moves_up, ulint match_mode,
btr_pcur_t *pcur, mtr_t *mtr) {
dberr_t err = DB_SUCCESS;
if (moves_up) {
if (!btr_pcur_move_to_next(pcur, mtr)) {
err = (match_mode != 0) ? DB_RECORD_NOT_FOUND : DB_END_OF_INDEX;
return (err);
}
} else {
if (!btr_pcur_move_to_prev(pcur, mtr)) {
err = (match_mode != 0) ? DB_RECORD_NOT_FOUND : DB_END_OF_INDEX;
return (err);
}
}
return (err);
}
/** Searches for rows in the database using cursor.
Function is for temporary tables that are not shared accross connections
and so lot of complexity is reduced especially locking and transaction related.
The cursor is an iterator over the table/index.
@param[out] buf buffer for the fetched row in MySQL format
@param[in] mode search mode PAGE_CUR_L
@param[in,out] prebuilt prebuilt struct for the table handler;
this contains the info to search_tuple,
index; if search tuple contains 0 field then
we position the cursor at start or the end of
index, depending on 'mode'
@param[in] match_mode 0 or ROW_SEL_EXACT or ROW_SEL_EXACT_PREFIX
@param[in] direction 0 or ROW_SEL_NEXT or ROW_SEL_PREV;
Note: if this is != 0, then prebuilt must has a
pcur with stored position! In opening of a
cursor 'direction' should be 0.
@return DB_SUCCESS or error code */
dberr_t row_search_no_mvcc(byte *buf, page_cur_mode_t mode,
row_prebuilt_t *prebuilt, ulint match_mode,
ulint direction) {
dict_index_t *index = prebuilt->index;
ut_ad(index->table->is_intrinsic());
const dtuple_t *search_tuple = prebuilt->search_tuple;
btr_pcur_t *pcur = prebuilt->pcur;
Row_sel_get_clust_rec_for_mysql row_sel_get_clust_rec_for_mysql;
const rec_t *result_rec = NULL;
const rec_t *clust_rec = NULL;
dberr_t err = DB_SUCCESS;
mem_heap_t *heap = NULL;
ulint offsets_[REC_OFFS_NORMAL_SIZE];
ulint *offsets = offsets_;
rec_offs_init(offsets_);
ut_ad(index && pcur && search_tuple);
/* Step-0: Re-use the cached mtr. */
mtr_t *mtr;
dict_index_t *clust_index = index->table->first_index();
if (!index->last_sel_cur) {
dict_allocate_mem_intrinsic_cache(index);
}
mtr = &index->last_sel_cur->mtr;
/* Step-1: Build the select graph. */
if (direction == 0 && prebuilt->sel_graph == NULL) {
row_prebuild_sel_graph(prebuilt);
}
que_thr_t *thr = que_fork_get_first_thr(prebuilt->sel_graph);
bool moves_up;
if (direction == 0) {
if (mode == PAGE_CUR_GE || mode == PAGE_CUR_G) {
moves_up = true;
} else {
moves_up = false;
}
} else if (direction == ROW_SEL_NEXT) {
moves_up = true;
} else {
moves_up = false;
}
/* Step-2: Open or Restore the cursor.
If search key is specified, cursor is open using the key else
cursor is open to return all the records. */
if (direction != 0) {
if (prebuilt->m_temp_read_shared && !prebuilt->m_temp_tree_modified) {
if (!mtr->is_active()) {
mtr_start(mtr);
}
/* This is an intrinsic table shared read, so we
do not rely on index->last_sel_cur, instead we rely
on "prebuilt->pcur", which supposes to position on
last read position for each read session. */
ut_ad(pcur->m_pos_state == BTR_PCUR_IS_POSITIONED);
err = row_search_traverse(moves_up, match_mode, pcur, mtr);
if (err != DB_SUCCESS) {
return (err); /* purecov: inspected */
}
} else if (index->last_sel_cur->invalid || prebuilt->m_temp_tree_modified) {
/* Index tree has changed and so active cached cursor is no more valid.
Re-set it based on the last selected position. */
index->last_sel_cur->release();
prebuilt->m_temp_tree_modified = false;
if (direction == ROW_SEL_NEXT && pcur->m_search_mode == PAGE_CUR_GE) {
pcur->m_search_mode = PAGE_CUR_G;
}
mtr_start(mtr);
mtr_set_log_mode(mtr, MTR_LOG_NO_REDO);
mem_heap_t *heap = mem_heap_create(256);
dtuple_t *tuple = dict_index_build_data_tuple(index, pcur->m_old_rec,
pcur->m_old_n_fields, heap);
btr_pcur_open_with_no_init(index, tuple, pcur->m_search_mode,
BTR_SEARCH_LEAF, pcur, 0, mtr);
mem_heap_free(heap);
} else {
/* Restore the cursor for reading next record from cache
information. */
ut_ad(index->last_sel_cur->rec != NULL);
pcur->m_btr_cur.page_cur.rec = index->last_sel_cur->rec;
pcur->m_btr_cur.page_cur.block = index->last_sel_cur->block;
err = row_search_traverse(moves_up, match_mode, pcur, mtr);
if (err != DB_SUCCESS) {
return (err);
}
}
} else {
/* There could be previous uncommitted transaction if SELECT
is operation as part of SELECT (IF NOT FOUND) INSERT
(IF DUPLICATE) UPDATE plan. */
index->last_sel_cur->release();
/* Capture table snapshot in form of trx-id. */
index->trx_id = dict_table_get_curr_table_sess_trx_id(index->table);
/* Fresh search commences. */
mtr_start(mtr);
dict_disable_redo_if_temporary(index->table, mtr);
if (dtuple_get_n_fields(search_tuple) > 0) {
btr_pcur_open_with_no_init(index, search_tuple, mode, BTR_SEARCH_LEAF,
pcur, 0, mtr);
} else if (mode == PAGE_CUR_G || mode == PAGE_CUR_L) {
btr_pcur_open_at_index_side(mode == PAGE_CUR_G, index, BTR_SEARCH_LEAF,
pcur, false, 0, mtr);
}
}
/* Step-3: Traverse the records filtering non-qualifiying records. */
for (/* No op */; err == DB_SUCCESS;
err = row_search_traverse(moves_up, match_mode, pcur, mtr)) {
const rec_t *rec = btr_pcur_get_rec(pcur);
if (page_rec_is_infimum(rec) || page_rec_is_supremum(rec) ||
rec_get_deleted_flag(rec, dict_table_is_comp(index->table))) {
/* The infimum record on a page cannot be in the
result set, and neither can a record lock be placed on
it: we skip such a record. */
continue;
}
offsets = rec_get_offsets(rec, index, offsets, ULINT_UNDEFINED, &heap);
/* Note that we cannot trust the up_match value in the cursor
at this place because we can arrive here after moving the
cursor! Thus we have to recompare rec and search_tuple to
determine if they match enough. */
if (match_mode == ROW_SEL_EXACT) {
/* Test if the index record matches completely to
search_tuple in prebuilt: if not, then we return with
DB_RECORD_NOT_FOUND */
if (0 != cmp_dtuple_rec(search_tuple, rec, index, offsets)) {
err = DB_RECORD_NOT_FOUND;
break;
}
} else if (match_mode == ROW_SEL_EXACT_PREFIX) {
if (!cmp_dtuple_is_prefix_of_rec(search_tuple, rec, index, offsets)) {
err = DB_RECORD_NOT_FOUND;
break;
}
}
/* Get the clustered index. We always need clustered index
record for snapshort verification. */
if (index != clust_index) {
err =
row_sel_get_clust_rec_for_mysql(prebuilt, index, rec, thr, &clust_rec,
&offsets, &heap, NULL, mtr, nullptr);
if (err != DB_SUCCESS) {
break;
}
if (rec_get_deleted_flag(clust_rec, dict_table_is_comp(index->table))) {
/* The record is delete marked in clustered
index. We can skip this record. */
continue;
}
result_rec = clust_rec;
} else {
result_rec = rec;
}
/* Step-4: Cache the row-id of selected row to prebuilt cache.*/
if (prebuilt->clust_index_was_generated) {
row_sel_store_row_id_to_prebuilt(prebuilt, result_rec, clust_index,
offsets);
}
/* Step-5: Convert selected record to MySQL format and
store it. */
if (prebuilt->template_type == ROW_MYSQL_DUMMY_TEMPLATE) {
const rec_t *ret_rec =
(index != clust_index && prebuilt->need_to_access_clustered)
? result_rec
: rec;
offsets =
rec_get_offsets(ret_rec, index, offsets, ULINT_UNDEFINED, &heap);
memcpy(buf + 4, ret_rec - rec_offs_extra_size(offsets),
rec_offs_size(offsets));
mach_write_to_4(buf, rec_offs_extra_size(offsets) + 4);
} else if (!row_sel_store_mysql_rec(buf, prebuilt, result_rec, NULL, TRUE,
clust_index, offsets, false, nullptr,
nullptr)) {
err = DB_ERROR;
break;
}
/* Step-6: Store cursor position to fetch next record.
MySQL calls this function iteratively get_next(), get_next()
fashion. */
ut_ad(err == DB_SUCCESS);
index->last_sel_cur->rec = btr_pcur_get_rec(pcur);
index->last_sel_cur->block = btr_pcur_get_block(pcur);
/* This is needed in order to restore the cursor if index
structure changes while SELECT is still active. */
pcur->m_old_rec = dict_index_copy_rec_order_prefix(
index, rec, &pcur->m_old_n_fields, &pcur->m_old_rec_buf,
&pcur->m_buf_size);
break;
}
if (err != DB_SUCCESS) {
index->last_sel_cur->release();
}
if (heap != NULL) {
mem_heap_free(heap);
}
return (err);
}
/** Extract virtual column data from a virtual index record and fill a dtuple
@param[in] rec the virtual (secondary) index record
@param[in] index the virtual index
@param[in,out] vrow the dtuple where data extract to
@param[in] heap memory heap to allocate memory
*/
static void row_sel_fill_vrow(const rec_t *rec, dict_index_t *index,
const dtuple_t **vrow, mem_heap_t *heap) {
ulint offsets_[REC_OFFS_NORMAL_SIZE];
ulint *offsets = offsets_;
rec_offs_init(offsets_);
ut_ad(!(*vrow));
offsets = rec_get_offsets(rec, index, offsets, ULINT_UNDEFINED, &heap);
*vrow =
dtuple_create_with_vcol(heap, 0, dict_table_get_n_v_cols(index->table));
/* Initialize all virtual row's mtype to DATA_MISSING */
dtuple_init_v_fld(*vrow);
for (ulint i = 0; i < dict_index_get_n_fields(index); i++) {
const dict_field_t *field;
const dict_col_t *col;
field = index->get_field(i);
col = field->col;
if (col->is_virtual()) {
const byte *data;
ulint len;
data = rec_get_nth_field(rec, offsets, i, &len);
const dict_v_col_t *vcol = reinterpret_cast<const dict_v_col_t *>(col);
dfield_t *dfield = dtuple_get_nth_v_field(*vrow, vcol->v_pos);
dfield_set_data(dfield, data, len);
col->copy_type(dfield_get_type(dfield));
}
}
}
/** The return type of row_compare_row_to_range() which summarizes information
about the relation between the row being processed, and the range of the scan */
struct row_to_range_relation_t {
/** true: we don't know, false: row is not in range */
bool row_can_be_in_range;
/** true: we don't know, false: gap has nothing in common with range */
bool gap_can_intersect_range;
/** true: row exactly matches end of range, false: we don't know */
bool row_must_be_at_end;
};
/** A helper function extracted from row_search_mvcc() which compares the row
being processed with the range of the scan.
It does not modify any of it's arguments and returns a summary of situation.
All the arguments are named the same way as local variables at place of call,
and have same values. */
static row_to_range_relation_t row_compare_row_to_range(
const bool set_also_gap_locks, const trx_t *const trx,
const ibool unique_search, const dict_index_t *const index,
const dict_index_t *const clust_index, const rec_t *const rec,
const ibool comp, const page_cur_mode_t mode, const ulint direction,
const dtuple_t *search_tuple, const ulint *const offsets,
const ibool moves_up, const row_prebuilt_t *const prebuilt) {
row_to_range_relation_t row_to_range_relation;
row_to_range_relation.row_can_be_in_range = true;
row_to_range_relation.gap_can_intersect_range = true;
row_to_range_relation.row_must_be_at_end = false;
/* We don't know how to compare row which is on supremum with range, but this
should not be a problem because row_search_mvcc "skips" over them without
calling our function */
ut_ad(!page_rec_is_supremum(rec));
if (page_rec_is_supremum(rec)) {
return (row_to_range_relation);
}
/* Try to place a lock on the index record; note that delete
marked records are a special case in a unique search. If there
is a non-delete marked record, then it is enough to lock its
existence with LOCK_REC_NOT_GAP. */
/* If we are doing a 'greater or equal than a primary key
value' search from a clustered index, and we find a record
that has that exact primary key value, then there is no need
to lock the gap before the record, because no insert in the
gap can be in our search range. That is, no phantom row can
appear that way.
An example: if col1 is the primary key, the search is WHERE
col1 >= 100, and we find a record where col1 = 100, then no
need to lock the gap before that record. */
if (!set_also_gap_locks || trx->skip_gap_locks() ||
(unique_search && !rec_get_deleted_flag(rec, comp)) ||
dict_index_is_spatial(index) ||
(index == clust_index && mode == PAGE_CUR_GE && direction == 0 &&
dtuple_get_n_fields_cmp(search_tuple) ==
dict_index_get_n_unique(index) &&
0 == cmp_dtuple_rec(search_tuple, rec, index, offsets))) {
row_to_range_relation.gap_can_intersect_range = false;
return (row_to_range_relation);
}
/* We don't know how to handle HANDLER interface */
if (prebuilt->used_in_HANDLER) {
return (row_to_range_relation);
}
/* While I believe that we handle semi-consistent reads correctly, the proof
is quite complicated and lingers on the fact that semi-consistent reads are
used only if we don't use gap locks. And fortunately, we've already checked
above that trx->skip_gap_locks() is false, so we don't have to go through the
whole reasoning about what exactly happens in case the row which is at the
end of the range got locked by another transaction, removed, purged, and while
we were doing semi-consistent read on it. */
ut_ad(!trx->skip_gap_locks());
ut_ad(prebuilt->row_read_type == ROW_READ_WITH_LOCKS);
/* Following heuristics are meant to avoid locking the row itself, or even
the gap before it, in case when the row is "after the end of range". The
difficulty here is in that the index itself can be declared as either
ascending or descending, separately for each column, and cursor can be
PAGE_CUR_G(E) or PAGE_CUR_L(E) etc., and direction of scan can be 0,
ROW_SEL_NEXT or ROW_SEL_PREV, and this might be a secondary index (with
duplicates). So we limit ourselves just to the cases, which are at the
same common, tested, actionable and easy to reason about.
In particular we only handle cases where we iterate the index in its
natural order. */
if (index == clust_index && (mode == PAGE_CUR_GE || mode == PAGE_CUR_G) &&
(direction == 0 || direction == ROW_SEL_NEXT) &&
prebuilt->is_reading_range()) {
ut_ad(moves_up);
const auto stop_len = dtuple_get_n_fields_cmp(prebuilt->m_stop_tuple);
if (0 < stop_len) {
const auto index_len = dict_index_get_n_unique(index);
ut_ad(prebuilt->m_mysql_handler->end_range != nullptr);
if (stop_len <= index_len) {
const auto cmp =
cmp_dtuple_rec(prebuilt->m_stop_tuple, rec, index, offsets);
if (cmp < 0) {
row_to_range_relation.row_can_be_in_range = false;
if (prebuilt->m_stop_tuple_found) {
ut_ad(stop_len == index_len);
ut_ad(direction != 0);
row_to_range_relation.gap_can_intersect_range = false;
return (row_to_range_relation);
}
return (row_to_range_relation);
}
if (cmp == 0) {
ut_ad(!prebuilt->m_stop_tuple_found);
row_to_range_relation.row_can_be_in_range =
prebuilt->m_mysql_handler->end_range->flag != HA_READ_BEFORE_KEY;
row_to_range_relation.row_must_be_at_end = stop_len == index_len;
return (row_to_range_relation);
}
}
}
}
return (row_to_range_relation);
}
/** Searches for rows in the database using cursor.
Function is mainly used for tables that are shared accorss connection and
so it employs technique that can help re-construct the rows that
transaction is suppose to see.
It also has optimization such as pre-caching the rows, using AHI, etc.
@param[out] buf buffer for the fetched row in MySQL format
@param[in] mode search mode PAGE_CUR_L
@param[in,out] prebuilt prebuilt struct for the table handler;
this contains the info to search_tuple,
index; if search tuple contains 0 field then
we position the cursor at start or the end of
index, depending on 'mode'
@param[in] match_mode 0 or ROW_SEL_EXACT or ROW_SEL_EXACT_PREFIX
@param[in] direction 0 or ROW_SEL_NEXT or ROW_SEL_PREV;
Note: if this is != 0, then prebuilt must has a
pcur with stored position! In opening of a
cursor 'direction' should be 0.
@return DB_SUCCESS or error code */
dberr_t row_search_mvcc(byte *buf, page_cur_mode_t mode,
row_prebuilt_t *prebuilt, ulint match_mode,
ulint direction) {
DBUG_TRACE;
dict_index_t *index = prebuilt->index;
ibool comp = dict_table_is_comp(index->table);
const dtuple_t *search_tuple = prebuilt->search_tuple;
btr_pcur_t *pcur = prebuilt->pcur;
trx_t *trx = prebuilt->trx;
dict_index_t *clust_index;
/* True if we are scanning a secondary index, but the template is based
on the primary index. */
bool clust_templ_for_sec;
que_thr_t *thr;
const rec_t *prev_rec = NULL;
const rec_t *rec = NULL;
byte *end_range_cache = NULL;
const dtuple_t *prev_vrow = NULL;
const dtuple_t *vrow = NULL;
const rec_t *result_rec = NULL;
const rec_t *clust_rec;
Row_sel_get_clust_rec_for_mysql row_sel_get_clust_rec_for_mysql;
dberr_t err = DB_SUCCESS;
ibool unique_search = FALSE;
ibool mtr_has_extra_clust_latch = FALSE;
ibool moves_up = FALSE;
bool set_also_gap_locks = true;
/* if the query is a plain locking SELECT, and the isolation level
is <= TRX_ISO_READ_COMMITTED, then this is set to FALSE */
ibool did_semi_consistent_read = FALSE;
/* if the returned record was locked and we did a semi-consistent
read (fetch the newest committed version), then this is set to
TRUE */
ulint next_offs;
ibool same_user_rec = FALSE;
mtr_t mtr;
mem_heap_t *heap = NULL;
ulint offsets_[REC_OFFS_NORMAL_SIZE];
ulint *offsets = offsets_;
ulint sec_offsets_[REC_OFFS_NORMAL_SIZE];
ulint *sec_offsets = nullptr;
ibool table_lock_waited = FALSE;
byte *next_buf = 0;
bool spatial_search = false;
ulint end_loop = 0;
lizard::AsofVisonWrapper asof_wrapper;
rec_offs_init(offsets_);
ut_ad(index && pcur && search_tuple);
ut_a(prebuilt->magic_n == ROW_PREBUILT_ALLOCATED);
ut_a(prebuilt->magic_n2 == ROW_PREBUILT_ALLOCATED);
ut_a(!trx->has_search_latch);
assert_lizard_dict_index_check(index);
assert_lizard_dict_table_check(index->table);
ut_ad(!pcur->m_cleanout_pages || pcur->m_cleanout_pages->is_empty());
ut_ad(!prebuilt->sample->enabled || index == index->table->first_index());
ut_ad(!prebuilt->sample->enabled || match_mode == 0);
/* We don't support FTS queries from the HANDLER interfaces, because
we implemented FTS as reversed inverted index with auxiliary tables.
So anything related to traditional index query would not apply to
it. */
if (prebuilt->index->type & DICT_FTS) {
return DB_END_OF_INDEX;
}
#ifdef UNIV_DEBUG
{
btrsea_sync_check check(trx->has_search_latch);
ut_ad(!sync_check_iterate(check));
}
#endif /* UNIV_DEBUG */
if (dict_table_is_discarded(prebuilt->table)) {
return DB_TABLESPACE_DELETED;
} else if (prebuilt->table->ibd_file_missing) {
return DB_TABLESPACE_NOT_FOUND;
} else if (!prebuilt->index_usable) {
return DB_MISSING_HISTORY;
} else if (prebuilt->index->is_corrupted()) {
return DB_CORRUPTION;
}
/* We need to get the virtual column values stored in secondary
index key, if this is covered index scan or virtual key read is
requested. */
bool need_vrow = dict_index_has_virtual(prebuilt->index) &&
(prebuilt->read_just_key || prebuilt->m_read_virtual_key);
/* Reset the new record lock info if trx_t::allow_semi_consistent().
Then we are able to remove the record locks set here on an
individual row. */
std::fill_n(prebuilt->new_rec_lock, row_prebuilt_t::LOCK_COUNT, false);
/*-------------------------------------------------------------*/
/* PHASE 1: Try to pop the row from the record buffer or from
the prefetch cache */
const auto record_buffer = row_sel_get_record_buffer(prebuilt);
if (UNIV_UNLIKELY(direction == 0)) {
trx->op_info = "starting index read";
prebuilt->n_rows_fetched = 0;
prebuilt->n_fetch_cached = 0;
prebuilt->fetch_cache_first = 0;
if (record_buffer != nullptr) {
record_buffer->reset();
}
if (prebuilt->sel_graph == NULL) {
/* Build a dummy select query graph */
row_prebuild_sel_graph(prebuilt);
}
} else {
trx->op_info = "fetching rows";
if (prebuilt->n_rows_fetched == 0) {
prebuilt->fetch_direction = direction;
}
if (UNIV_UNLIKELY(direction != prebuilt->fetch_direction)) {
if (UNIV_UNLIKELY(prebuilt->n_fetch_cached > 0)) {
ut_error;
/* TODO: scrollable cursor: restore cursor to
the place of the latest returned row,
or better: prevent caching for a scroll
cursor! */
}
prebuilt->n_rows_fetched = 0;
prebuilt->n_fetch_cached = 0;
prebuilt->fetch_cache_first = 0;
/* A record buffer is not used for scroll cursors.
Otherwise, it would have to be reset here too. */
ut_ad(record_buffer == nullptr);
} else if (UNIV_LIKELY(prebuilt->n_fetch_cached > 0)) {
row_sel_dequeue_cached_row_for_mysql(buf, prebuilt);
prebuilt->n_rows_fetched++;
err = DB_SUCCESS;
goto func_exit;
} else if (prebuilt->m_end_range == true) {
prebuilt->m_end_range = false;
err = DB_RECORD_NOT_FOUND;
goto func_exit;
}
/* The prefetch cache is exhausted, so fetch_cache_first
should point to the beginning of the cache. */
ut_ad(prebuilt->fetch_cache_first == 0);
if (record_buffer != nullptr && record_buffer->is_out_of_range()) {
/* The previous returned row was popped from
the fetch cache, but the end of the range was
reached while filling the cache, so there are
no more rows to put into the cache. */
err = DB_RECORD_NOT_FOUND;
goto func_exit;
}
prebuilt->n_rows_fetched++;
if (prebuilt->n_rows_fetched > 1000000000) {
/* Prevent wrap-over */
prebuilt->n_rows_fetched = 500000000;
}
mode = pcur->m_search_mode;
}
/* In a search where at most one record in the index may match, we
can use a LOCK_REC_NOT_GAP type record lock when locking a
non-delete-marked matching record.
Note that in a unique secondary index there may be different
delete-marked versions of a record where only the primary key
values differ: thus in a secondary index we must use next-key
locks when locking delete-marked records. */
if (match_mode == ROW_SEL_EXACT && dict_index_is_unique(index) &&
dtuple_get_n_fields(search_tuple) == dict_index_get_n_unique(index) &&
(index->is_clustered() || !dtuple_contains_null(search_tuple))) {
/* Note above that a UNIQUE secondary index can contain many
rows with the same key value if one of the columns is the SQL
null. A clustered index under MySQL can never contain null
columns because we demand that all the columns in primary key
are non-null. */
unique_search = TRUE;
/* Even if the condition is unique, MySQL seems to try to
retrieve also a second row if a primary key contains more than
1 column. Return immediately if this is not a HANDLER
command. */
if (UNIV_UNLIKELY(direction != 0 && !prebuilt->used_in_HANDLER)) {
err = DB_RECORD_NOT_FOUND;
goto func_exit;
}
}
/* We don't support sequential scan for Rtree index, because it
is no meaning to do so. */
if (dict_index_is_spatial(index) && !RTREE_SEARCH_MODE(mode)) {
err = DB_END_OF_INDEX;
goto func_exit;
}
mtr_start(&mtr);
/*-------------------------------------------------------------*/
/* PHASE 2: Try fast adaptive hash index search if possible */
/* Next test if this is the special case where we can use the fast
adaptive hash index to try the search. Since we must release the
search system latch when we retrieve an externally stored field, we
cannot use the adaptive hash index in a search in the case the row
may be long and there may be externally stored fields */
if (UNIV_UNLIKELY(direction == 0) && unique_search && btr_search_enabled &&
index->is_clustered() && !prebuilt->templ_contains_blob &&
!prebuilt->used_in_HANDLER &&
(prebuilt->mysql_row_len < UNIV_PAGE_SIZE / 8) && !prebuilt->innodb_api) {
mode = PAGE_CUR_GE;
if (trx->mysql_n_tables_locked == 0 && !prebuilt->ins_sel_stmt &&
prebuilt->select_lock_type == LOCK_NONE &&
trx->isolation_level > TRX_ISO_READ_UNCOMMITTED &&
// MVCC::is_view_active(trx->read_view)) {
trx->vision.is_active()) {
/* This is a SELECT query done as a consistent read,
and the read view has already been allocated:
let us try a search shortcut through the hash
index.
NOTE that we must also test that
mysql_n_tables_locked == 0, because this might
also be INSERT INTO ... SELECT ... or
CREATE TABLE ... SELECT ... . Our algorithm is
NOT prepared to inserts interleaved with the SELECT,
and if we try that, we can deadlock on the adaptive
hash index semaphore! */
ut_a(!trx->has_search_latch);
rw_lock_s_lock(btr_get_search_latch(index));
trx->has_search_latch = true;
/* set as-of condition vision if need */
asof_wrapper.set_as_of_vision(prebuilt);
switch (row_sel_try_search_shortcut_for_mysql(&rec, prebuilt, &offsets,
&heap, &mtr)) {
case SEL_FOUND:
/* At this point, rec is protected by
a page latch that was acquired by
row_sel_try_search_shortcut_for_mysql().
The latch will not be released until
mtr_commit(&mtr). */
ut_ad(!rec_get_deleted_flag(rec, comp));
if (prebuilt->idx_cond) {
switch (row_search_idx_cond_check(buf, prebuilt, rec, offsets)) {
case ICP_NO_MATCH:
case ICP_OUT_OF_RANGE:
goto shortcut_mismatch;
case ICP_MATCH:
goto shortcut_match;
}
}
if (!row_sel_store_mysql_rec(buf, prebuilt, rec, NULL, FALSE, index,
offsets, false, nullptr, nullptr)) {
/* Only fresh inserts may contain
incomplete externally stored
columns. Pretend that such
records do not exist. Such
records may only be accessed
at the READ UNCOMMITTED
isolation level or when
rolling back a recovered
transaction. Rollback happens
at a lower level, not here. */
/* Proceed as in case SEL_RETRY. */
break;
}
shortcut_match:
mtr_commit(&mtr);
/* NOTE that we do NOT store the cursor
position */
err = DB_SUCCESS;
rw_lock_s_unlock(btr_get_search_latch(index));
trx->has_search_latch = false;
goto func_exit;
case SEL_EXHAUSTED:
shortcut_mismatch:
mtr_commit(&mtr);
err = DB_RECORD_NOT_FOUND;
rw_lock_s_unlock(btr_get_search_latch(index));
trx->has_search_latch = false;
/* NOTE that we do NOT store the cursor
position */
goto func_exit;
case SEL_RETRY:
break;
default:
ut_ad(0);
}
mtr_commit(&mtr);
mtr_start(&mtr);
rw_lock_s_unlock(btr_get_search_latch(index));
trx->has_search_latch = false;
}
}
/*-------------------------------------------------------------*/
/* PHASE 3: Open or restore index cursor position */
spatial_search = dict_index_is_spatial(index) && mode >= PAGE_CUR_CONTAIN;
/* The state of a running trx can only be changed by the
thread that is currently serving the transaction. Because we
are that thread, we can read trx->state without holding any
mutex. */
ut_ad(prebuilt->sql_stat_start || trx->state == TRX_STATE_ACTIVE);
ut_ad(!trx_is_started(trx) || trx->state == TRX_STATE_ACTIVE);
ut_ad(prebuilt->sql_stat_start || prebuilt->select_lock_type != LOCK_NONE ||
trx->vision.is_active() || srv_read_only_mode);
trx_start_if_not_started(trx, false);
if (prebuilt->table->skip_gap_locks() ||
(trx->skip_gap_locks() && prebuilt->select_lock_type != LOCK_NONE &&
trx->mysql_thd != NULL && thd_is_select(trx->mysql_thd))) {
/* It is a plain locking SELECT and the isolation
level is low: do not lock gaps */
/* Reads on DD tables dont require gap-locks as serializability
between different DDL statements is achieved using
metadata locks */
set_also_gap_locks = false;
}
/* Note that if the search mode was GE or G, then the cursor
naturally moves upward (in fetch next) in alphabetical order,
otherwise downward */
if (direction == 0) {
if (mode == PAGE_CUR_GE || mode == PAGE_CUR_G || mode >= PAGE_CUR_CONTAIN) {
moves_up = TRUE;
}
} else if (direction == ROW_SEL_NEXT) {
moves_up = TRUE;
}
thr = que_fork_get_first_thr(prebuilt->sel_graph);
que_thr_move_to_run_state_for_mysql(thr, trx);
clust_index = index->table->first_index();
clust_templ_for_sec =
index != clust_index && prebuilt->need_to_access_clustered;
/* Do some start-of-statement preparations */
if (!prebuilt->sql_stat_start) {
/* No need to set an intention lock or assign a read view */
//if (!MVCC::is_view_active(trx->read_view)
if (!trx->vision.is_active() && !srv_read_only_mode &&
prebuilt->select_lock_type == LOCK_NONE) {
ib::error(ER_IB_MSG_1031) << "MySQL is trying to perform a"
" consistent read but the read view is not"
" assigned!";
trx_print(stderr, trx, 600);
fputc('\n', stderr);
ut_error;
}
} else if (prebuilt->select_lock_type == LOCK_NONE) {
/* This is a consistent read */
/* Assign a read view for the query */
if (!srv_read_only_mode) {
trx_assign_read_view(trx);
/* convert ctx to innobase, only set once */
if ((err = lizard::convert_fbq_ctx_to_innobase(prebuilt))
!= DB_SUCCESS) {
goto as_of_error;
}
}
prebuilt->sql_stat_start = FALSE;
} else {
wait_table_again:
err = lock_table(0, index->table,
prebuilt->select_lock_type == LOCK_S ? LOCK_IS : LOCK_IX,
thr);
if (err != DB_SUCCESS) {
table_lock_waited = TRUE;
goto lock_table_wait;
}
prebuilt->sql_stat_start = FALSE;
}
/* set as-of condition vision if need */
asof_wrapper.set_as_of_vision(prebuilt);
/* Open or restore index cursor position */
if (UNIV_LIKELY(direction != 0)) {
if (spatial_search) {
/* R-Tree access does not need to do
cursor position and resposition */
goto next_rec;
}
ibool need_to_process = sel_restore_position_for_mysql(
&same_user_rec, BTR_SEARCH_LEAF, pcur, prebuilt, moves_up, &mtr);
if (UNIV_UNLIKELY(need_to_process)) {
if (UNIV_UNLIKELY(prebuilt->row_read_type ==
ROW_READ_DID_SEMI_CONSISTENT)) {
/* We did a semi-consistent read,
but the record was removed in
the meantime. */
prebuilt->row_read_type = ROW_READ_TRY_SEMI_CONSISTENT;
}
} else if (UNIV_LIKELY(prebuilt->row_read_type !=
ROW_READ_DID_SEMI_CONSISTENT)) {
/* The cursor was positioned on the record
that we returned previously. If we need
to repeat a semi-consistent read as a
pessimistic locking read, the record
cannot be skipped. */
goto next_rec;
}
} else if (dtuple_get_n_fields(search_tuple) > 0) {
pcur->m_btr_cur.thr = thr;
if (dict_index_is_spatial(index)) {
bool need_pred_lock = set_also_gap_locks && !trx->skip_gap_locks() &&
prebuilt->select_lock_type != LOCK_NONE;
if (!prebuilt->rtr_info) {
prebuilt->rtr_info = rtr_create_rtr_info(
need_pred_lock, true, btr_pcur_get_btr_cur(pcur), index);
prebuilt->rtr_info->search_tuple = search_tuple;
prebuilt->rtr_info->search_mode = mode;
rtr_info_update_btr(btr_pcur_get_btr_cur(pcur), prebuilt->rtr_info);
} else {
rtr_info_reinit_in_cursor(btr_pcur_get_btr_cur(pcur), index,
need_pred_lock);
prebuilt->rtr_info->search_tuple = search_tuple;
prebuilt->rtr_info->search_mode = mode;
}
}
btr_pcur_open_with_no_init(index, search_tuple, mode, BTR_SEARCH_LEAF, pcur,
0, &mtr);
pcur->m_trx_if_known = trx;
rec = btr_pcur_get_rec(pcur);
if (!moves_up && !page_rec_is_supremum(rec) && set_also_gap_locks &&
!trx->skip_gap_locks() && prebuilt->select_lock_type != LOCK_NONE &&
!dict_index_is_spatial(index)) {
/* Try to place a gap lock on the next index record
to prevent phantoms in ORDER BY ... DESC queries */
const rec_t *next_rec = page_rec_get_next_const(rec);
offsets =
rec_get_offsets(next_rec, index, offsets, ULINT_UNDEFINED, &heap);
err = sel_set_rec_lock(pcur, next_rec, index, offsets,
prebuilt->select_mode, prebuilt->select_lock_type,
LOCK_GAP, thr, &mtr);
switch (err) {
case DB_SUCCESS_LOCKED_REC:
err = DB_SUCCESS;
case DB_SUCCESS:
break;
case DB_SKIP_LOCKED:
case DB_LOCK_NOWAIT:
ut_ad(0);
goto next_rec;
default:
goto lock_wait_or_error;
}
}
} else if (prebuilt->sample->enabled) {
ut_ad(mode == PAGE_CUR_G);
btr_sample_pcur_open(prebuilt->sample, index, &mtr);
} else if (mode == PAGE_CUR_G || mode == PAGE_CUR_L) {
btr_pcur_open_at_index_side(mode == PAGE_CUR_G, index, BTR_SEARCH_LEAF,
pcur, false, 0, &mtr);
}
rec_loop:
DEBUG_SYNC_C("row_search_rec_loop");
prebuilt->lob_undo_reset();
if (trx_is_interrupted(trx)) {
if (!spatial_search) {
btr_pcur_store_position(pcur, &mtr);
}
err = DB_INTERRUPTED;
goto normal_return;
}
/*-------------------------------------------------------------*/
/* PHASE 4: Look for matching records in a loop */
rec = btr_pcur_get_rec(pcur);
ut_ad(!!page_rec_is_comp(rec) == comp);
if (page_rec_is_infimum(rec)) {
/* The infimum record on a page cannot be in the result set,
and neither can a record lock be placed on it: we skip such
a record. */
prev_rec = NULL;
goto next_rec;
}
if (page_rec_is_supremum(rec)) {
DBUG_EXECUTE_IF(
"compare_end_range", if (end_loop < 100) { end_loop = 100; });
/** Compare the last record of the page with end range
passed to InnoDB when there is no ICP and number of
loops in row_search_mvcc for rows found but not
reporting due to search views etc. */
if (prev_rec != NULL && !prebuilt->innodb_api &&
prebuilt->m_mysql_handler->end_range != NULL &&
prebuilt->idx_cond == false && end_loop >= 100) {
dict_index_t *key_index = prebuilt->index;
if (end_range_cache == NULL) {
end_range_cache =
static_cast<byte *>(ut_malloc_nokey(prebuilt->mysql_row_len));
}
if (clust_templ_for_sec) {
/** Secondary index record but the template
based on PK. */
key_index = clust_index;
}
/** Create offsets based on prebuilt index. */
offsets = rec_get_offsets(prev_rec, prebuilt->index, offsets,
ULINT_UNDEFINED, &heap);
if (row_sel_store_mysql_rec(end_range_cache, prebuilt, prev_rec,
prev_vrow, clust_templ_for_sec, key_index,
offsets, clust_templ_for_sec,
prebuilt->get_lob_undo(), nullptr)) {
if (row_search_end_range_check(end_range_cache, prev_rec, prebuilt,
clust_templ_for_sec, offsets,
record_buffer)) {
/** In case of prebuilt->fetch,
set the error in prebuilt->end_range. */
if (next_buf != nullptr) {
prebuilt->m_end_range = true;
}
err = DB_RECORD_NOT_FOUND;
goto normal_return;
}
}
DEBUG_SYNC_C("allow_insert");
}
if (set_also_gap_locks && !trx->skip_gap_locks() &&
prebuilt->select_lock_type != LOCK_NONE &&
!dict_index_is_spatial(index)) {
/* Try to place a lock on the index record */
offsets = rec_get_offsets(rec, index, offsets, ULINT_UNDEFINED, &heap);
err = sel_set_rec_lock(pcur, rec, index, offsets, prebuilt->select_mode,
prebuilt->select_lock_type, LOCK_ORDINARY, thr,
&mtr);
switch (err) {
case DB_SUCCESS_LOCKED_REC:
err = DB_SUCCESS;
case DB_SUCCESS:
break;
case DB_SKIP_LOCKED:
case DB_LOCK_NOWAIT:
ut_ad(0);
default:
goto lock_wait_or_error;
}
DEBUG_SYNC_C("allow_insert");
}
/* A page supremum record cannot be in the result set: skip
it now that we have placed a possible lock on it */
prev_rec = NULL;
goto next_rec;
}
/*-------------------------------------------------------------*/
/* Do sanity checks in case our cursor has bumped into page
corruption */
if (comp) {
next_offs = rec_get_next_offs(rec, TRUE);
if (UNIV_UNLIKELY(next_offs < PAGE_NEW_SUPREMUM)) {
goto wrong_offs;
}
} else {
next_offs = rec_get_next_offs(rec, FALSE);
if (UNIV_UNLIKELY(next_offs < PAGE_OLD_SUPREMUM)) {
goto wrong_offs;
}
}
if (UNIV_UNLIKELY(next_offs >= UNIV_PAGE_SIZE - PAGE_DIR)) {
wrong_offs:
if (srv_force_recovery == 0 || moves_up == FALSE) {
ib::error(ER_IB_MSG_1032)
<< "Rec address " << static_cast<const void *>(rec)
<< ", buf block fix count "
<< btr_cur_get_block(btr_pcur_get_btr_cur(pcur))->page.buf_fix_count;
ib::error(ER_IB_MSG_1033)
<< "Index corruption: rec offs " << page_offset(rec) << " next offs "
<< next_offs << ", page no " << page_get_page_no(page_align(rec))
<< ", index " << index->name << " of table " << index->table->name
<< ". Run CHECK TABLE. You may need to"
" restore from a backup, or dump + drop +"
" reimport the table.";
ut_ad(0);
err = DB_CORRUPTION;
goto lock_wait_or_error;
} else {
/* The user may be dumping a corrupt table. Jump
over the corruption to recover as much as possible. */
ib::info(ER_IB_MSG_1034)
<< "Index corruption: rec offs " << page_offset(rec) << " next offs "
<< next_offs << ", page no " << page_get_page_no(page_align(rec))
<< ", index " << index->name << " of table " << index->table->name
<< ". We try to skip the rest of the page.";
btr_pcur_move_to_last_on_page(pcur, &mtr);
prev_rec = NULL;
goto next_rec;
}
}
/*-------------------------------------------------------------*/
/* Calculate the 'offsets' associated with 'rec' */
ut_ad(fil_page_index_page_check(btr_pcur_get_page(pcur)));
ut_ad(btr_page_get_index_id(btr_pcur_get_page(pcur)) == index->id);
offsets = rec_get_offsets(rec, index, offsets, ULINT_UNDEFINED, &heap);
if (UNIV_UNLIKELY(srv_force_recovery > 0)) {
if (!rec_validate(rec, offsets) ||
!btr_index_rec_validate(rec, index, FALSE)) {
ib::info(ER_IB_MSG_1035)
<< "Index corruption: rec offs " << page_offset(rec) << " next offs "
<< next_offs << ", page no " << page_get_page_no(page_align(rec))
<< ", index " << index->name << " of table " << index->table->name
<< ". We try to skip the record.";
prev_rec = NULL;
goto next_rec;
}
}
prev_rec = rec;
/* Note that we cannot trust the up_match value in the cursor at this
place because we can arrive here after moving the cursor! Thus
we have to recompare rec and search_tuple to determine if they
match enough. */
if (match_mode == ROW_SEL_EXACT) {
/* Test if the index record matches completely to search_tuple
in prebuilt: if not, then we return with DB_RECORD_NOT_FOUND */
/* fputs("Comparing rec and search tuple\n", stderr); */
if (0 != cmp_dtuple_rec(search_tuple, rec, index, offsets)) {
if (set_also_gap_locks && !trx->skip_gap_locks() &&
prebuilt->select_lock_type != LOCK_NONE &&
!dict_index_is_spatial(index)) {
err = sel_set_rec_lock(pcur, rec, index, offsets, prebuilt->select_mode,
prebuilt->select_lock_type, LOCK_GAP, thr, &mtr);
switch (err) {
case DB_SUCCESS_LOCKED_REC:
case DB_SUCCESS:
break;
case DB_SKIP_LOCKED:
case DB_LOCK_NOWAIT:
ut_ad(0);
default:
goto lock_wait_or_error;
}
}
btr_pcur_store_position(pcur, &mtr);
/* The found record was not a match, but may be used
as NEXT record (index_next). Set the relative position
to BTR_PCUR_BEFORE, to reflect that the position of
the persistent cursor is before the found/stored row
(pcur->m_old_rec). */
ut_ad(pcur->m_rel_pos == BTR_PCUR_ON);
pcur->m_rel_pos = BTR_PCUR_BEFORE;
err = DB_RECORD_NOT_FOUND;
goto normal_return;
}
} else if (match_mode == ROW_SEL_EXACT_PREFIX) {
if (!cmp_dtuple_is_prefix_of_rec(search_tuple, rec, index, offsets)) {
if (set_also_gap_locks && !trx->skip_gap_locks() &&
prebuilt->select_lock_type != LOCK_NONE &&
!dict_index_is_spatial(index)) {
err = sel_set_rec_lock(pcur, rec, index, offsets, prebuilt->select_mode,
prebuilt->select_lock_type, LOCK_GAP, thr, &mtr);
switch (err) {
case DB_SUCCESS_LOCKED_REC:
case DB_SUCCESS:
break;
case DB_SKIP_LOCKED:
case DB_LOCK_NOWAIT:
ut_ad(0);
default:
goto lock_wait_or_error;
}
}
btr_pcur_store_position(pcur, &mtr);
/* The found record was not a match, but may be used
as NEXT record (index_next). Set the relative position
to BTR_PCUR_BEFORE, to reflect that the position of
the persistent cursor is before the found/stored row
(pcur->old_rec). */
ut_ad(pcur->m_rel_pos == BTR_PCUR_ON);
pcur->m_rel_pos = BTR_PCUR_BEFORE;
err = DB_RECORD_NOT_FOUND;
goto normal_return;
}
}
/* We are ready to look at a possible new index entry in the result
set: the cursor is now placed on a user record */
if (prebuilt->select_lock_type != LOCK_NONE) {
auto row_to_range_relation = row_compare_row_to_range(
set_also_gap_locks, trx, unique_search, index, clust_index, rec, comp,
mode, direction, search_tuple, offsets, moves_up, prebuilt);
ulint lock_type;
if (row_to_range_relation.row_can_be_in_range) {
if (row_to_range_relation.gap_can_intersect_range) {
lock_type = LOCK_ORDINARY;
} else {
lock_type = LOCK_REC_NOT_GAP;
}
} else {
if (row_to_range_relation.gap_can_intersect_range) {
lock_type = LOCK_GAP;
} else {
err = DB_RECORD_NOT_FOUND;
goto normal_return;
}
}
err = sel_set_rec_lock(pcur, rec, index, offsets, prebuilt->select_mode,
prebuilt->select_lock_type, lock_type, thr, &mtr);
switch (err) {
const rec_t *old_vers;
case DB_SUCCESS_LOCKED_REC:
if (trx->allow_semi_consistent()) {
/* Note that a record of
prebuilt->index was locked. */
ut_ad(!prebuilt->new_rec_lock[row_prebuilt_t::LOCK_PCUR]);
prebuilt->new_rec_lock[row_prebuilt_t::LOCK_PCUR] = true;
}
err = DB_SUCCESS;
// Fall through
case DB_SUCCESS:
if (row_to_range_relation.row_must_be_at_end) {
prebuilt->m_stop_tuple_found = true;
}
break;
case DB_SKIP_LOCKED:
goto next_rec;
case DB_LOCK_WAIT:
/* Lock wait for R-tree should already
be handled in sel_set_rtr_rec_lock() */
ut_ad(!dict_index_is_spatial(index));
/* Never unlock rows that were part of a conflict. */
std::fill_n(prebuilt->new_rec_lock, row_prebuilt_t::LOCK_COUNT, false);
if (UNIV_LIKELY(prebuilt->row_read_type !=
ROW_READ_TRY_SEMI_CONSISTENT) ||
unique_search || index != clust_index) {
goto lock_wait_or_error;
}
/* The following call returns 'offsets' associated with 'old_vers' */
row_sel_build_committed_vers_for_mysql(clust_index, prebuilt, rec,
&offsets, &heap, &old_vers,
need_vrow ? &vrow : NULL, &mtr);
/* Check whether it was a deadlock or not, if not
a deadlock and the transaction had to wait then
release the lock it is waiting on. */
DEBUG_SYNC_C("semi_consistent_read_would_wait");
err = lock_trx_handle_wait(trx);
switch (err) {
case DB_SUCCESS:
/* The lock was granted while we were
searching for the last committed version.
Do a normal locking read. */
offsets =
rec_get_offsets(rec, index, offsets, ULINT_UNDEFINED, &heap);
goto locks_ok;
case DB_DEADLOCK:
goto lock_wait_or_error;
case DB_LOCK_WAIT:
ut_ad(!dict_index_is_spatial(index));
err = DB_SUCCESS;
break;
default:
ut_error;
}
if (old_vers == NULL) {
/* The row was not yet committed */
goto next_rec;
}
did_semi_consistent_read = TRUE;
rec = old_vers;
prev_rec = rec;
break;
case DB_RECORD_NOT_FOUND:
if (dict_index_is_spatial(index)) {
goto next_rec;
} else {
goto lock_wait_or_error;
}
default:
goto lock_wait_or_error;
}
locks_ok:
if (err == DB_SUCCESS && !row_to_range_relation.row_can_be_in_range) {
err = DB_RECORD_NOT_FOUND;
goto normal_return;
}
} else {
/* This is a non-locking consistent read: if necessary, fetch
a previous version of the record */
if (trx->isolation_level == TRX_ISO_READ_UNCOMMITTED) {
/* Do nothing: we let a non-locking SELECT read the
latest version of the record */
} else if (index == clust_index) {
/* Fetch a previous version of the row if the current
one is not visible in the snapshot; if we have a very
high force recovery level set, we try to avoid crashes
by skipping this lookup */
if (trx_get_vision(trx)->is_asof_gcn()) {
dberr_t gp_error = DB_SUCCESS;
bool see = lizard::gp_clust_rec_cons_read_sees(
trx, rec, index, offsets, pcur, trx_get_vision(trx), &gp_error);
if (gp_error != DB_SUCCESS) {
err = gp_error;
goto lock_wait_or_error;
} else {
if (!see) {
rec_t *old_vers;
/* The following call returns 'offsets' associated with 'old_vers'
*/
err = row_sel_build_prev_vers_for_mysql(
&trx->vision, clust_index, prebuilt, rec, &offsets, &heap,
&old_vers, need_vrow ? &vrow : NULL, &mtr,
prebuilt->get_lob_undo());
if (err != DB_SUCCESS) {
goto lock_wait_or_error;
}
if (old_vers == NULL) {
/* The row did not exist yet in
the read view */
goto next_rec;
}
rec = old_vers;
prev_rec = rec;
}
}
} else if (srv_force_recovery < 5 &&
!lock_clust_rec_cons_read_sees(rec, index, offsets, pcur,
trx_get_vision(trx))) {
rec_t *old_vers;
/* The following call returns 'offsets' associated with 'old_vers' */
err = row_sel_build_prev_vers_for_mysql(
&trx->vision, clust_index, prebuilt, rec, &offsets, &heap,
&old_vers, need_vrow ? &vrow : NULL, &mtr,
prebuilt->get_lob_undo());
if (err != DB_SUCCESS) {
goto lock_wait_or_error;
}
if (old_vers == NULL) {
/* The row did not exist yet in
the read view */
goto next_rec;
}
rec = old_vers;
prev_rec = rec;
}
} else {
/* We are looking into a non-clustered index,
and to get the right version of the record we
have to look also into the clustered index: this
is necessary, because we can only get the undo
information via the clustered index record. */
ut_ad(!index->is_clustered());
if (!srv_read_only_mode &&
!lock_sec_rec_cons_read_sees(rec, index, &trx->vision)) {
/* We should look at the clustered index.
However, as this is a non-locking read,
we can skip the clustered index lookup if
the condition does not match the secondary
index entry. */
switch (row_search_idx_cond_check(buf, prebuilt, rec, offsets)) {
case ICP_NO_MATCH:
goto next_rec;
case ICP_OUT_OF_RANGE:
err = DB_RECORD_NOT_FOUND;
goto idx_cond_failed;
case ICP_MATCH:
goto requires_clust_rec;
}
ut_error;
}
}
}
/* NOTE that at this point rec can be an old version of a clustered
index record built for a consistent read. We cannot assume after this
point that rec is on a buffer pool page. Functions like
page_rec_is_comp() cannot be used! */
if (rec_get_deleted_flag(rec, comp)) {
/* The record is delete-marked: we can skip it */
if (!prebuilt->table->is_temporary()) prebuilt->rds_rows_read_del_mark++;
if (trx->allow_semi_consistent() &&
prebuilt->select_lock_type != LOCK_NONE && !did_semi_consistent_read) {
/* No need to keep a lock on a delete-marked record
if we do not want to use next-key locking. */
row_unlock_for_mysql(prebuilt, TRUE);
}
/* This is an optimization to skip setting the next key lock
on the record that follows this delete-marked record. This
optimization works because of the unique search criteria
which precludes the presence of a range lock between this
delete marked record and the record following it.
For now this is applicable only to clustered indexes while
doing a unique search except for HANDLER queries because
HANDLER allows NEXT and PREV even in unique search on
clustered index. There is scope for further optimization
applicable to unique secondary indexes. Current behaviour is
to widen the scope of a lock on an already delete marked record
if the same record is deleted twice by the same transaction */
if (index == clust_index && unique_search && !prebuilt->used_in_HANDLER) {
err = DB_RECORD_NOT_FOUND;
goto normal_return;
}
goto next_rec;
}
/* Check if the record matches the index condition. */
switch (row_search_idx_cond_check(buf, prebuilt, rec, offsets)) {
case ICP_NO_MATCH:
if (did_semi_consistent_read) {
row_unlock_for_mysql(prebuilt, TRUE);
}
goto next_rec;
case ICP_OUT_OF_RANGE:
err = DB_RECORD_NOT_FOUND;
goto idx_cond_failed;
case ICP_MATCH:
break;
}
/* Get the clustered index record if needed, if we did not do the
search using the clustered index. */
if (index != clust_index && prebuilt->need_to_access_clustered) {
requires_clust_rec:
ut_ad(index != clust_index);
/* We use a 'goto' to the preceding label if a consistent
read of a secondary index record requires us to look up old
versions of the associated clustered index record. */
ut_ad(rec_offs_validate(rec, index, offsets));
/* It was a non-clustered index and we must fetch also the
clustered index record */
mtr_has_extra_clust_latch = TRUE;
ut_ad(!vrow);
/* The following call returns 'offsets' associated with
'clust_rec'. Note that 'clust_rec' can be an old version
built for a consistent read. */
err = row_sel_get_clust_rec_for_mysql(
prebuilt, index, rec, thr, &clust_rec, &offsets, &heap,
need_vrow ? &vrow : NULL, &mtr, prebuilt->get_lob_undo());
switch (err) {
case DB_SUCCESS:
if (clust_rec == NULL) {
/* The record did not exist in the read view */
ut_ad(prebuilt->select_lock_type == LOCK_NONE ||
dict_index_is_spatial(index));
goto next_rec;
}
break;
case DB_SKIP_LOCKED:
goto next_rec;
case DB_SUCCESS_LOCKED_REC:
ut_a(clust_rec != NULL);
if (trx->allow_semi_consistent()) {
/* Note that the clustered index record
was locked. */
ut_ad(!prebuilt->new_rec_lock[row_prebuilt_t::LOCK_CLUST_PCUR]);
prebuilt->new_rec_lock[row_prebuilt_t::LOCK_CLUST_PCUR] = true;
}
err = DB_SUCCESS;
break;
default:
vrow = NULL;
goto lock_wait_or_error;
}
if (rec_get_deleted_flag(clust_rec, comp)) {
/* The record is delete marked: we can skip it */
if (!prebuilt->table->is_temporary()) prebuilt->rds_rows_read_del_mark++;
if (trx->allow_semi_consistent() &&
prebuilt->select_lock_type != LOCK_NONE) {
/* No need to keep a lock on a delete-marked
record if we do not want to use next-key
locking. */
row_unlock_for_mysql(prebuilt, TRUE);
}
goto next_rec;
}
if (need_vrow && !vrow) {
if (!heap) {
heap = mem_heap_create(100);
}
row_sel_fill_vrow(rec, index, &vrow, heap);
}
result_rec = clust_rec;
ut_ad(rec_offs_validate(result_rec, clust_index, offsets));
if (prebuilt->idx_cond) {
/* Convert the record to MySQL format. We were
unable to do this in row_search_idx_cond_check(),
because the condition is on the secondary index
and the requested column is in the clustered index.
We convert all fields, including those that
may have been used in ICP, because the
secondary index may contain a column prefix
rather than the full column. Also, as noted
in Bug #56680, the column in the secondary
index may be in the wrong case, and the
authoritative case is in result_rec, the
appropriate version of the clustered index record. */
if (!row_sel_store_mysql_rec(buf, prebuilt, result_rec, vrow, TRUE,
clust_index, offsets, false, nullptr,
nullptr)) {
goto next_rec;
}
}
/* TODO: This is for a temporary fix, will be removed later */
/* Check duplicate rec for spatial index. */
if (dict_index_is_spatial(index) && rec_get_deleted_flag(rec, comp) &&
prebuilt->rtr_info->is_dup) {
dtuple_t *clust_row;
row_ext_t *ext = nullptr;
rtr_mbr_t clust_mbr;
rtr_mbr_t index_mbr;
ulint *index_offsets;
const dtuple_t *index_entry;
bool *is_dup_rec = prebuilt->rtr_info->is_dup;
*is_dup_rec = false;
if (!heap) {
heap = mem_heap_create(100);
}
clust_row = row_build(ROW_COPY_DATA, clust_index, clust_rec, offsets,
NULL, NULL, NULL, &ext, heap);
index_entry = row_build_index_entry(clust_row, ext, index, heap);
rtr_get_mbr_from_tuple(index_entry, &clust_mbr);
index_offsets = rec_get_offsets(rec, index, NULL, ULINT_UNDEFINED, &heap);
rtr_get_mbr_from_rec(rec, index_offsets, &index_mbr);
if (mbr_equal_cmp(index->rtr_srs.get(), &clust_mbr, &index_mbr)) {
*is_dup_rec = true;
}
}
} else {
result_rec = rec;
}
/* We found a qualifying record 'result_rec'. At this point,
'offsets' are associated with 'result_rec'. */
ut_ad(rec_offs_validate(result_rec, result_rec != rec ? clust_index : index,
offsets));
ut_ad(!rec_get_deleted_flag(result_rec, comp));
/* If we cannot prefetch records, we should not have a record buffer.
See ha_innobase::ha_is_record_buffer_wanted(). */
ut_ad(prebuilt->can_prefetch_records() || record_buffer == nullptr);
/* Decide whether to prefetch extra rows.
At this point, the clustered index record is protected
by a page latch that was acquired when pcur was positioned.
The latch will not be released until mtr_commit(&mtr). */
if (record_buffer != nullptr ||
((match_mode == ROW_SEL_EXACT ||
prebuilt->n_rows_fetched >= MYSQL_FETCH_CACHE_THRESHOLD) &&
prebuilt->can_prefetch_records())) {
/* Inside an update, for example, we do not cache rows,
since we may use the cursor position to do the actual
update, that is why we require ...lock_type == LOCK_NONE.
Since we keep space in prebuilt only for the BLOBs of
a single row, we cannot cache rows in the case there
are BLOBs in the fields to be fetched. In HANDLER (note:
the HANDLER statement, not the handler class) we do
not cache rows because there the cursor is a scrollable
cursor. */
const auto max_rows_to_cache =
record_buffer ? record_buffer->max_records() : MYSQL_FETCH_CACHE_SIZE;
ut_a(prebuilt->n_fetch_cached < max_rows_to_cache);
/* We only convert from InnoDB row format to MySQL row
format when ICP is disabled. */
if (!prebuilt->idx_cond) {
/* We use next_buf to track the allocation of buffers
where we store and enqueue the buffers for our
pre-fetch optimisation.
If next_buf == 0 then we store the converted record
directly into the MySQL record buffer (buf). If it is
!= 0 then we allocate a pre-fetch buffer and store the
converted record there.
If the conversion fails and the MySQL record buffer
was not written to then we reset next_buf so that
we can re-use the MySQL record buffer in the next
iteration. */
byte *prev_buf = next_buf;
next_buf = next_buf ? row_sel_fetch_last_buf(prebuilt) : buf;
if (!row_sel_store_mysql_rec(next_buf, prebuilt, result_rec, vrow,
result_rec != rec,
result_rec != rec ? clust_index : index,
offsets, false, nullptr, nullptr)) {
if (next_buf == buf) {
ut_a(prebuilt->n_fetch_cached == 0);
next_buf = 0;
}
/* Only fresh inserts may contain incomplete
externally stored columns. Pretend that such
records do not exist. Such records may only be
accessed at the READ UNCOMMITTED isolation
level or when rolling back a recovered
transaction. Rollback happens at a lower
level, not here. */
goto next_rec;
}
/* If we are filling a server-provided buffer, and the
server has pushed down an end range condition, evaluate
the condition to prevent that we read too many rows. */
if (record_buffer != nullptr &&
prebuilt->m_mysql_handler->end_range != nullptr) {
/* If the end-range condition refers to a
virtual column and we are reading from the
clustered index, next_buf does not have the
value of the virtual column. Get the offsets in
the secondary index so that we can read the
virtual column from the index. */
if (clust_templ_for_sec &&
prebuilt->m_mysql_handler->m_virt_gcol_in_end_range) {
if (sec_offsets == nullptr) {
rec_offs_init(sec_offsets_);
sec_offsets = sec_offsets_;
}
sec_offsets =
rec_get_offsets(rec, index, sec_offsets, ULINT_UNDEFINED, &heap);
}
if (row_search_end_range_check(next_buf, rec, prebuilt,
clust_templ_for_sec, sec_offsets,
record_buffer)) {
if (next_buf != buf) {
record_buffer->remove_last();
}
next_buf = prev_buf;
err = DB_RECORD_NOT_FOUND;
goto normal_return;
}
}
if (next_buf != buf) {
row_sel_enqueue_cache_row_for_mysql(next_buf, prebuilt);
}
} else {
row_sel_enqueue_cache_row_for_mysql(buf, prebuilt);
}
if (prebuilt->n_fetch_cached < max_rows_to_cache) {
goto next_rec;
}
} else {
/* We cannot use a record buffer for this scan, so assert that
we don't have one. If we have a record buffer here,
ha_innobase::is_record_buffer_wanted() should be updated so
that a buffer is not allocated unnecessarily. */
ut_ad(record_buffer == nullptr);
if (UNIV_UNLIKELY(prebuilt->template_type == ROW_MYSQL_DUMMY_TEMPLATE)) {
/* CHECK TABLE: fetch the row */
if (result_rec != rec && !prebuilt->need_to_access_clustered) {
/* We used 'offsets' for the clust
rec, recalculate them for 'rec' */
offsets = rec_get_offsets(rec, index, offsets, ULINT_UNDEFINED, &heap);
result_rec = rec;
}
memcpy(buf + 4, result_rec - rec_offs_extra_size(offsets),
rec_offs_size(offsets));
mach_write_to_4(buf, rec_offs_extra_size(offsets) + 4);
} else if (!prebuilt->idx_cond && !prebuilt->innodb_api) {
/* The record was not yet converted to MySQL format. */
if (!row_sel_store_mysql_rec(
buf, prebuilt, result_rec, vrow, result_rec != rec,
result_rec != rec ? clust_index : index, offsets, false,
prebuilt->get_lob_undo(), nullptr)) {
/* Only fresh inserts may contain
incomplete externally stored
columns. Pretend that such records do
not exist. Such records may only be
accessed at the READ UNCOMMITTED
isolation level or when rolling back a
recovered transaction. Rollback
happens at a lower level, not here. */
goto next_rec;
}
}
if (prebuilt->clust_index_was_generated) {
row_sel_store_row_id_to_prebuilt(prebuilt, result_rec,
result_rec == rec ? index : clust_index,
offsets);
}
}
/* From this point on, 'offsets' are invalid. */
/* We have an optimization to save CPU time: if this is a consistent
read on a unique condition on the clustered index, then we do not
store the pcur position, because any fetch next or prev will anyway
return 'end of file'. Exceptions are locking reads and the MySQL
HANDLER command where the user can move the cursor with PREV or NEXT
even after a unique search. */
err = DB_SUCCESS;
idx_cond_failed:
if (!unique_search || !index->is_clustered() || direction != 0 ||
prebuilt->select_lock_type != LOCK_NONE || prebuilt->used_in_HANDLER ||
prebuilt->innodb_api) {
/* Inside an update always store the cursor position */
if (!spatial_search) {
btr_pcur_store_position(pcur, &mtr);
}
if (prebuilt->innodb_api && (btr_pcur_get_rec(pcur) != result_rec)) {
ulint rec_size = rec_offs_size(offsets);
if (!prebuilt->innodb_api_rec_size ||
(prebuilt->innodb_api_rec_size < rec_size)) {
prebuilt->innodb_api_buf = static_cast<byte *>(
mem_heap_alloc(prebuilt->cursor_heap, rec_size));
prebuilt->innodb_api_rec_size = rec_size;
}
prebuilt->innodb_api_rec =
rec_copy(prebuilt->innodb_api_buf, result_rec, offsets);
}
}
goto normal_return;
next_rec:
if (end_loop >= 99 && need_vrow && vrow == NULL && prev_rec != NULL) {
if (!heap) {
heap = mem_heap_create(100);
}
prev_vrow = NULL;
row_sel_fill_vrow(prev_rec, index, &prev_vrow, heap);
} else {
prev_vrow = vrow;
}
end_loop++;
/* Reset the old and new "did semi-consistent read" flags. */
if (UNIV_UNLIKELY(prebuilt->row_read_type == ROW_READ_DID_SEMI_CONSISTENT)) {
prebuilt->row_read_type = ROW_READ_TRY_SEMI_CONSISTENT;
}
did_semi_consistent_read = FALSE;
std::fill_n(prebuilt->new_rec_lock, row_prebuilt_t::LOCK_COUNT, false);
vrow = NULL;
/*-------------------------------------------------------------*/
/* PHASE 5: Move the cursor to the next index record */
/* NOTE: For moves_up==FALSE, the mini-transaction will be
committed and restarted every time when switching b-tree
pages. For moves_up==TRUE in index condition pushdown, we can
scan an entire secondary index tree within a single
mini-transaction. As long as the prebuilt->idx_cond does not
match, we do not need to consult the clustered index or
return records to MySQL, and thus we can avoid repositioning
the cursor. What prevents us from buffer-fixing all leaf pages
within the mini-transaction is the btr_leaf_page_release()
call in btr_pcur_move_to_next_page(). Only the leaf page where
the cursor is positioned will remain buffer-fixed.
For R-tree spatial search, we also commit the mini-transaction
each time */
if (mtr_has_extra_clust_latch || spatial_search) {
/* If we have extra cluster latch, we must commit
mtr if we are moving to the next non-clustered
index record, because we could break the latching
order if we would access a different clustered
index page right away without releasing the previous. */
/* No need to do store restore for R-tree */
if (!spatial_search) {
btr_pcur_store_position(pcur, &mtr);
}
mtr_commit(&mtr);
mtr_has_extra_clust_latch = FALSE;
mtr_start(&mtr);
if (!spatial_search &&
sel_restore_position_for_mysql(&same_user_rec, BTR_SEARCH_LEAF, pcur,
prebuilt, moves_up, &mtr)) {
goto rec_loop;
}
}
if (moves_up) {
bool move;
if (spatial_search) {
move = rtr_pcur_move_to_next(search_tuple, mode, prebuilt->select_mode,
pcur, 0, &mtr);
} else if (prebuilt->sample->enabled) {
move = btr_sample_pcur_next(prebuilt->sample, &mtr);
} else {
move = btr_pcur_move_to_next(pcur, &mtr);
}
if (!move) {
not_moved:
if (!spatial_search) {
btr_pcur_store_position(pcur, &mtr);
}
if (match_mode != 0) {
err = DB_RECORD_NOT_FOUND;
} else {
err = DB_END_OF_INDEX;
}
goto normal_return;
}
} else {
if (UNIV_UNLIKELY(!btr_pcur_move_to_prev(pcur, &mtr))) {
goto not_moved;
}
}
goto rec_loop;
lock_wait_or_error:
/* Reset the old and new "did semi-consistent read" flags. */
if (UNIV_UNLIKELY(prebuilt->row_read_type == ROW_READ_DID_SEMI_CONSISTENT)) {
prebuilt->row_read_type = ROW_READ_TRY_SEMI_CONSISTENT;
}
did_semi_consistent_read = FALSE;
/*-------------------------------------------------------------*/
if (!dict_index_is_spatial(index)) {
btr_pcur_store_position(pcur, &mtr);
}
lock_table_wait:
mtr_commit(&mtr);
mtr_has_extra_clust_latch = FALSE;
trx->error_state = err;
/* The following is a patch for MySQL */
if (thr->is_active && err != DB_GP_WAIT) {
que_thr_stop_for_mysql(thr);
}
thr->lock_state = QUE_THR_LOCK_ROW;
if (row_mysql_handle_errors(&err, trx, thr, NULL)) {
/* It was a lock wait, and it ended */
thr->lock_state = QUE_THR_LOCK_NOLOCK;
mtr_start(&mtr);
/* Table lock waited, go try to obtain table lock
again */
if (table_lock_waited) {
table_lock_waited = FALSE;
goto wait_table_again;
}
if (!dict_index_is_spatial(index)) {
sel_restore_position_for_mysql(&same_user_rec, BTR_SEARCH_LEAF, pcur,
prebuilt, moves_up, &mtr);
}
if (!same_user_rec && trx->allow_semi_consistent()) {
/* Since we were not able to restore the cursor
on the same user record, we cannot use
row_unlock_for_mysql() to unlock any records, and
we must thus reset the new rec lock info. Since
in lock0lock.cc we have blocked the inheriting of gap
X-locks, we actually do not have any new record locks
set in this case.
Note that if we were able to restore on the 'same'
user record, it is still possible that we were actually
waiting on a delete-marked record, and meanwhile
it was removed by purge and inserted again by some
other user. But that is no problem, because in
rec_loop we will again try to set a lock, and
new_rec_lock_info in trx will be right at the end. */
std::fill_n(prebuilt->new_rec_lock, row_prebuilt_t::LOCK_COUNT, false);
}
mode = pcur->m_search_mode;
goto rec_loop;
}
thr->lock_state = QUE_THR_LOCK_NOLOCK;
goto func_exit;
as_of_error:
/*-------------------------------------------------------------*/
que_thr_stop_for_mysql_no_error(thr, trx);
ut_ad(err != DB_SUCCESS);
goto func_exit;
normal_return:
/*-------------------------------------------------------------*/
que_thr_stop_for_mysql_no_error(thr, trx);
mtr_commit(&mtr);
/* Rollback blocking transactions from hit list for high priority
transaction, if any. We should not be holding latches here as
we are going to rollback the blocking transactions. */
trx_kill_blocking(trx);
DEBUG_SYNC_C("row_search_for_mysql_before_return");
if (prebuilt->idx_cond != 0) {
/* When ICP is active we don't write to the MySQL buffer
directly, only to buffers that are enqueued in the pre-fetch
queue. We need to dequeue the first buffer and copy the contents
to the record buffer that was passed in by MySQL. */
if (prebuilt->n_fetch_cached > 0) {
row_sel_dequeue_cached_row_for_mysql(buf, prebuilt);
err = DB_SUCCESS;
}
} else if (next_buf != 0) {
/* We may or may not have enqueued some buffers to the
pre-fetch queue, but we definitely wrote to the record
buffer passed to use by MySQL. */
DEBUG_SYNC_C("row_search_cached_row");
err = DB_SUCCESS;
}
#ifdef UNIV_DEBUG
if (dict_index_is_spatial(index) && err != DB_SUCCESS &&
err != DB_END_OF_INDEX && err != DB_INTERRUPTED) {
rtr_node_path_t *path = pcur->m_btr_cur.rtr_info->path;
ut_ad(path->empty());
}
#endif
func_exit:
trx->op_info = "";
if (end_range_cache != NULL) {
ut_free(end_range_cache);
}
if (heap != NULL) {
mem_heap_free(heap);
}
/* Set or reset the "did semi-consistent read" flag on return.
The flag did_semi_consistent_read is set if and only if
the record being returned was fetched with a semi-consistent read. */
ut_ad(prebuilt->row_read_type != ROW_READ_WITH_LOCKS ||
!did_semi_consistent_read);
if (prebuilt->row_read_type != ROW_READ_WITH_LOCKS) {
if (did_semi_consistent_read) {
prebuilt->row_read_type = ROW_READ_DID_SEMI_CONSISTENT;
} else {
prebuilt->row_read_type = ROW_READ_TRY_SEMI_CONSISTENT;
}
}
#ifdef UNIV_DEBUG
{
btrsea_sync_check check(trx->has_search_latch);
ut_ad(!sync_check_iterate(check));
}
#endif /* UNIV_DEBUG */
DEBUG_SYNC_C("innodb_row_search_for_mysql_exit");
prebuilt->lob_undo_reset();
ut_a(!trx->has_search_latch);
lizard::row_cleanout_after_read(prebuilt);
return err;
}
/** Count rows in a R-Tree leaf level.
@return DB_SUCCESS if successful */
dberr_t row_count_rtree_recs(
row_prebuilt_t *prebuilt, /*!< in: prebuilt struct for the
table handle; this contains the info
of search_tuple, index; if search
tuple contains 0 fields then we
position the cursor at the start or
the end of the index, depending on
'mode' */
ulint *n_rows, /*!< out: number of entries
seen in the consistent read */
ulint *n_dups) /*!< out: number of dup entries */
{
dict_index_t *index = prebuilt->index;
dberr_t ret = DB_SUCCESS;
mtr_t mtr;
mem_heap_t *heap;
dtuple_t *entry;
dtuple_t *search_entry = prebuilt->search_tuple;
ulint entry_len;
ulint i;
byte *buf;
bool is_dup = false;
ut_a(dict_index_is_spatial(index));
*n_rows = 0;
*n_dups = 0;
heap = mem_heap_create(256);
/* Build a search tuple. */
entry_len = dict_index_get_n_fields(index);
entry = dtuple_create(heap, entry_len);
for (i = 0; i < entry_len; i++) {
const dict_field_t *ind_field = index->get_field(i);
const dict_col_t *col = ind_field->col;
dfield_t *dfield = dtuple_get_nth_field(entry, i);
if (i == 0) {
double *mbr;
double tmp_mbr[SPDIMS * 2];
dfield->type.mtype = DATA_GEOMETRY;
dfield->type.prtype |= DATA_GIS_MBR;
/* Allocate memory for mbr field */
mbr = static_cast<double *>(mem_heap_alloc(heap, DATA_MBR_LEN));
/* Set mbr field data. */
dfield_set_data(dfield, mbr, DATA_MBR_LEN);
for (uint j = 0; j < SPDIMS; j++) {
tmp_mbr[j * 2] = DBL_MAX;
tmp_mbr[j * 2 + 1] = -DBL_MAX;
}
dfield_write_mbr(dfield, tmp_mbr);
continue;
}
dfield->type.mtype = col->mtype;
dfield->type.prtype = col->prtype;
}
prebuilt->search_tuple = entry;
ulint bufsize = ut_max(UNIV_PAGE_SIZE, prebuilt->mysql_row_len);
buf = static_cast<byte *>(ut_malloc_nokey(bufsize));
ulint cnt = 1000;
ut_ad(!index->table->is_intrinsic());
ret = row_search_mvcc(buf, PAGE_CUR_WITHIN, prebuilt, 0, 0);
prebuilt->rtr_info->is_dup = &is_dup;
loop:
/* Check thd->killed every 1,000 scanned rows */
if (--cnt == 0) {
if (trx_is_interrupted(prebuilt->trx)) {
ret = DB_INTERRUPTED;
goto func_exit;
}
cnt = 1000;
}
switch (ret) {
case DB_SUCCESS:
break;
case DB_DEADLOCK:
case DB_LOCK_TABLE_FULL:
case DB_LOCK_WAIT_TIMEOUT:
case DB_INTERRUPTED:
goto func_exit;
default:
/* fall through (this error is ignored by CHECK TABLE) */
case DB_END_OF_INDEX:
ret = DB_SUCCESS;
func_exit:
/* This may be pointing to a local variable. */
prebuilt->rtr_info->is_dup = nullptr;
prebuilt->search_tuple = search_entry;
ut_free(buf);
mem_heap_free(heap);
return (ret);
}
*n_rows = *n_rows + 1;
if (is_dup) {
*n_dups = *n_dups + 1;
is_dup = false;
}
ret = row_search_mvcc(buf, PAGE_CUR_WITHIN, prebuilt, 0, ROW_SEL_NEXT);
goto loop;
}
/** Read the AUTOINC column from the current row. If the value is less than
0 and the type is not unsigned then we reset the value to 0.
@return value read from the column */
static ib_uint64_t row_search_autoinc_read_column(
dict_index_t *index, /*!< in: index to read from */
const rec_t *rec, /*!< in: current rec */
ulint col_no, /*!< in: column number */
ulint mtype, /*!< in: column main type */
ibool unsigned_type) /*!< in: signed or unsigned flag */
{
ulint len;
const byte *data;
ib_uint64_t value;
mem_heap_t *heap = NULL;
ulint offsets_[REC_OFFS_NORMAL_SIZE];
ulint *offsets = offsets_;
rec_offs_init(offsets_);
offsets = rec_get_offsets(rec, index, offsets, col_no + 1, &heap);
if (rec_offs_nth_sql_null(offsets, col_no)) {
/* There is no non-NULL value in the auto-increment column. */
value = 0;
goto func_exit;
}
data = rec_get_nth_field(rec, offsets, col_no, &len);
value = row_parse_int(data, len, mtype, unsigned_type);
func_exit:
if (UNIV_LIKELY_NULL(heap)) {
mem_heap_free(heap);
}
return (value);
}
/** Get the maximum and non-delete-marked record in an index.
@param[in] index index tree
@param[in,out] mtr mini-transaction (may be committed and restarted)
@return maximum record, page s-latched in mtr
@retval NULL if there are no records, or if all of them are delete-marked */
static const rec_t *row_search_get_max_rec(dict_index_t *index, mtr_t *mtr) {
btr_pcur_t pcur;
const rec_t *rec;
/* Open at the high/right end (false), and init cursor */
btr_pcur_open_at_index_side(false, index, BTR_SEARCH_LEAF, &pcur, true, 0,
mtr);
do {
const page_t *page;
page = btr_pcur_get_page(&pcur);
rec = page_find_rec_last_not_deleted(page);
if (page_rec_is_user_rec(rec)) {
break;
} else {
rec = NULL;
}
btr_pcur_move_before_first_on_page(&pcur);
} while (btr_pcur_move_to_prev(&pcur, mtr));
btr_pcur_close(&pcur);
return (rec);
}
/** Read the max AUTOINC value from an index.
@return DB_SUCCESS if all OK else error code, DB_RECORD_NOT_FOUND if
column name can't be found in index */
dberr_t row_search_max_autoinc(
dict_index_t *index, /*!< in: index to search */
const char *col_name, /*!< in: name of autoinc column */
ib_uint64_t *value) /*!< out: AUTOINC value read */
{
dict_field_t *dfield = index->get_field(0);
dberr_t error = DB_SUCCESS;
*value = 0;
if (strcmp(col_name, dfield->name) != 0) {
error = DB_RECORD_NOT_FOUND;
} else {
mtr_t mtr;
const rec_t *rec;
mtr_start(&mtr);
rec = row_search_get_max_rec(index, &mtr);
if (rec != NULL) {
ibool unsigned_type = (dfield->col->prtype & DATA_UNSIGNED);
*value = row_search_autoinc_read_column(index, rec, 0, dfield->col->mtype,
unsigned_type);
}
mtr_commit(&mtr);
}
return (error);
}
/** Convert the innodb_table_stats clustered index record to
table_stats format.
@param[in] clust_rec clustered index record
@param[in] clust_index clustered index
@param[in] clust_offsets offsets of the clustered index
record
@param[out] tbl_stats table_stats information
to be filled. */
static void convert_to_table_stats_record(rec_t *clust_rec,
dict_index_t *clust_index,
ulint *clust_offsets,
TableStatsRecord &tbl_stats) {
for (ulint i = 0; i < rec_offs_n_fields(clust_offsets); i++) {
const byte *data;
ulint len;
data = rec_get_nth_field(clust_rec, clust_offsets, i, &len);
if (len == UNIV_SQL_NULL) {
continue;
}
tbl_stats.set_data(data, i, len);
}
}
/** Search the record present in innodb_table_stats table using
db_name, table_name and fill it in table stats structure.
@param[in] db_name database name
@param[in] tbl_name table name
@param[out] table_stats stats table structure.
@return true if successful else false. */
bool row_search_table_stats(const char *db_name, const char *tbl_name,
TableStatsRecord &table_stats) {
mtr_t mtr;
btr_pcur_t pcur;
rec_t *rec;
bool move = true;
ulint *offsets;
dict_table_t *table = dict_sys->table_stats;
dict_index_t *clust_index = table->first_index();
dtuple_t *dtuple;
dfield_t *dfield;
bool found_rec = false;
mem_heap_t *heap = mem_heap_create(1000);
dtuple = dtuple_create(heap, clust_index->n_uniq);
dict_index_copy_types(dtuple, clust_index, clust_index->n_uniq);
dfield = dtuple_get_nth_field(dtuple, TableStatsRecord::DB_NAME_COL_NO);
dfield_set_data(dfield, db_name, strlen(db_name));
dfield = dtuple_get_nth_field(dtuple, TableStatsRecord::TABLE_NAME_COL_NO);
dfield_set_data(dfield, tbl_name, strlen(tbl_name));
mtr_start(&mtr);
btr_pcur_open_with_no_init(clust_index, dtuple, PAGE_CUR_GE, BTR_SEARCH_LEAF,
&pcur, 0, &mtr);
for (; move == true; move = btr_pcur_move_to_next(&pcur, &mtr)) {
rec = btr_pcur_get_rec(&pcur);
offsets = rec_get_offsets(rec, clust_index, NULL, ULINT_UNDEFINED, &heap);
if (page_rec_is_infimum(rec) || page_rec_is_supremum(rec)) {
continue;
}
if (0 != cmp_dtuple_rec(dtuple, rec, clust_index, offsets)) {
break;
}
if (rec_get_deleted_flag(rec, dict_table_is_comp(table))) {
continue;
}
found_rec = true;
convert_to_table_stats_record(rec, clust_index, offsets, table_stats);
}
mtr_commit(&mtr);
mem_heap_free(heap);
return (found_rec);
}
/** Search the record present in innodb_index_stats using
db_name, table name and index_name and fill the
cardinality for the each column.
@param[in] db_name database name
@param[in] tbl_name table name
@param[in] index_name index name
@param[in] col_offset offset of the column in the index
@param[out] cardinality cardinality of the column.
@return true if successful else false. */
bool row_search_index_stats(const char *db_name, const char *tbl_name,
const char *index_name, ulint col_offset,
ulonglong *cardinality) {
mtr_t mtr;
btr_pcur_t pcur;
rec_t *rec;
bool move = true;
ulint *offsets;
dict_table_t *table = dict_sys->index_stats;
dict_index_t *clust_index = table->first_index();
dtuple_t *dtuple;
dfield_t *dfield;
mem_heap_t *heap = mem_heap_create(1000);
ulint n_recs = 0;
/** Number of fields to search in the table. */
static constexpr unsigned N_SEARCH_FIELDS = 3;
/** Column number of innodb_index_stats.database_name. */
static constexpr unsigned DB_NAME_COL_NO = 0;
/** Column number of innodb_index_stats.table_name. */
static constexpr unsigned TABLE_NAME_COL_NO = 1;
/** Column number of innodb_index_stats.index_name. */
static constexpr unsigned INDEX_NAME_COL_NO = 2;
/** Column number of innodb_index_stats.stat_value. */
static constexpr unsigned STAT_VALUE_COL_NO = 5;
ulint cardinality_index_offset = clust_index->get_col_pos(STAT_VALUE_COL_NO);
/** Search the innodb_index_stats table using
(database_name, table_name, index_name). */
dtuple = dtuple_create(heap, N_SEARCH_FIELDS);
dict_index_copy_types(dtuple, clust_index, N_SEARCH_FIELDS);
dfield = dtuple_get_nth_field(dtuple, DB_NAME_COL_NO);
dfield_set_data(dfield, db_name, strlen(db_name));
dfield = dtuple_get_nth_field(dtuple, TABLE_NAME_COL_NO);
dfield_set_data(dfield, tbl_name, strlen(tbl_name));
dfield = dtuple_get_nth_field(dtuple, INDEX_NAME_COL_NO);
dfield_set_data(dfield, index_name, strlen(index_name));
mtr_start(&mtr);
btr_pcur_open_with_no_init(clust_index, dtuple, PAGE_CUR_GE, BTR_SEARCH_LEAF,
&pcur, 0, &mtr);
for (; move == true; move = btr_pcur_move_to_next(&pcur, &mtr)) {
rec = btr_pcur_get_rec(&pcur);
offsets = rec_get_offsets(rec, clust_index, NULL, ULINT_UNDEFINED, &heap);
if (page_rec_is_infimum(rec) || page_rec_is_supremum(rec)) {
continue;
}
if (0 != cmp_dtuple_rec(dtuple, rec, clust_index, offsets)) {
break;
}
if (rec_get_deleted_flag(rec, dict_table_is_comp(table))) {
continue;
}
if (n_recs == col_offset) {
const byte *data;
ulint len;
data = rec_get_nth_field(rec, offsets, cardinality_index_offset, &len);
*cardinality = static_cast<ulonglong>(round(mach_read_from_8(data)));
mtr_commit(&mtr);
mem_heap_free(heap);
return (true);
}
n_recs++;
}
mtr_commit(&mtr);
mem_heap_free(heap);
return (false);
}
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