polardbxengine/storage/innobase/include/row0sel.h

508 lines
24 KiB
C

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/** @file include/row0sel.h
Select
Created 12/19/1997 Heikki Tuuri
*******************************************************/
#ifndef row0sel_h
#define row0sel_h
#include "univ.i"
#include "btr0pcur.h"
#include "data0data.h"
#include "dict0stats.h"
#include "dict0types.h"
#include "pars0sym.h"
#include "que0types.h"
#include "read0types.h"
#include "row0mysql.h"
#include "row0types.h"
#include "trx0types.h"
/** 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 */
/** 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 */
/** 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 */
/** Gets the plan node for the nth table in a join.
@param[in] node select node
@param[in] i get ith plan node
@return plan node */
UNIV_INLINE
plan_t *sel_node_get_nth_plan(sel_node_t *node, ulint i);
/** 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 */
/** Performs an execution step of an open or close cursor statement node.
@return query thread to run next or NULL */
UNIV_INLINE
que_thr_t *open_step(que_thr_t *thr); /*!< in: query thread */
/** 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 */
/** 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);
// clang-format off
/** Convert a row in the Innobase format to a row in the MySQL format.
Note that the template in prebuilt may advise us to copy only a few
columns to mysql_rec, other columns are left blank. All columns may not
be needed in the query.
@param[out] mysql_rec row in the MySQL format
@param[in,out] prebuilt prebuilt structure
@param[in] rec Innobase record in the index
which was described in prebuilt's
template, or in the clustered index;
must be protected by a page latch
@param[in] vrow virtual columns
@param[in] rec_clust true if rec is in the clustered index instead
of prebuilt->index
@param[in] index index of rec
@param[in] offsets array returned by rec_get_offsets(rec)
@param[in] clust_templ_for_sec true if rec belongs to secondary index
but the prebuilt->template is in
clustered index format and it
is 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.
@return true on success, false if not all columns could be retrieved */
// clang-format on
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);
/** 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. */
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 */
/** Searches for rows in the database. This is used in the interface to
MySQL. This function opens a cursor, and also implements fetch next
and fetch prev. NOTE that if we do a search with a full key value
from a unique index (ROW_SEL_EXACT), then we will not store the cursor
position and fetch next or fetch prev must not be tried to the cursor!
@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, DB_RECORD_NOT_FOUND, DB_END_OF_INDEX, DB_DEADLOCK,
DB_LOCK_TABLE_FULL, DB_CORRUPTION, or DB_TOO_BIG_RECORD */
UNIV_INLINE
dberr_t row_search_for_mysql(byte *buf, page_cur_mode_t mode,
row_prebuilt_t *prebuilt, ulint match_mode,
ulint direction)
MY_ATTRIBUTE((warn_unused_result));
/** Searches for rows in the database using cursor.
function is meant for temporary table that are not shared accross connection
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) MY_ATTRIBUTE((warn_unused_result));
/** 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) MY_ATTRIBUTE((warn_unused_result));
/** 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
seen in the consistent read */
/** Read the max AUTOINC value from an index.
@return DB_SUCCESS if all OK else error code */
dberr_t row_search_max_autoinc(
dict_index_t *index, /*!< in: index to search */
const char *col_name, /*!< in: autoinc column name */
ib_uint64_t *value) /*!< out: AUTOINC value read */
MY_ATTRIBUTE((warn_unused_result));
/** A structure for caching column values for prefetched rows */
struct sel_buf_t {
byte *data; /*!< data, or NULL; if not NULL, this field
has allocated memory which must be explicitly
freed; can be != NULL even when len is
UNIV_SQL_NULL */
ulint len; /*!< data length or UNIV_SQL_NULL */
ulint val_buf_size;
/*!< size of memory buffer allocated for data:
this can be more than len; this is defined
when data != NULL */
};
/** Query plan */
struct plan_t {
dict_table_t *table; /*!< table struct in the dictionary
cache */
dict_index_t *index; /*!< table index used in the search */
btr_pcur_t pcur; /*!< persistent cursor used to search
the index */
ibool asc; /*!< TRUE if cursor traveling upwards */
ibool pcur_is_open; /*!< TRUE if pcur has been positioned
and we can try to fetch new rows */
ibool cursor_at_end; /*!< TRUE if the cursor is open but
we know that there are no more
qualifying rows left to retrieve from
the index tree; NOTE though, that
there may still be unprocessed rows in
the prefetch stack; always FALSE when
pcur_is_open is FALSE */
ibool stored_cursor_rec_processed;
/*!< TRUE if the pcur position has been
stored and the record it is positioned
on has already been processed */
que_node_t **tuple_exps; /*!< array of expressions
which are used to calculate
the field values in the search
tuple: there is one expression
for each field in the search
tuple */
dtuple_t *tuple; /*!< search tuple */
page_cur_mode_t mode; /*!< search mode: PAGE_CUR_G, ... */
ulint n_exact_match; /*!< number of first fields in
the search tuple which must be
exactly matched */
ibool unique_search; /*!< TRUE if we are searching an
index record with a unique key */
ulint n_rows_fetched; /*!< number of rows fetched using pcur
after it was opened */
ulint n_rows_prefetched; /*!< number of prefetched rows cached
for fetch: fetching several rows in
the same mtr saves CPU time */
ulint first_prefetched; /*!< index of the first cached row in
select buffer arrays for each column */
ibool no_prefetch; /*!< no prefetch for this table */
sym_node_list_t columns; /*!< symbol table nodes for the columns
to retrieve from the table */
UT_LIST_BASE_NODE_T(func_node_t)
end_conds; /*!< conditions which determine the
fetch limit of the index segment we
have to look at: when one of these
fails, the result set has been
exhausted for the cursor in this
index; these conditions are normalized
so that in a comparison the column
for this table is the first argument */
UT_LIST_BASE_NODE_T(func_node_t)
other_conds; /*!< the rest of search conditions we can
test at this table in a join */
ibool must_get_clust; /*!< TRUE if index is a non-clustered
index and we must also fetch the
clustered index record; this is the
case if the non-clustered record does
not contain all the needed columns, or
if this is a single-table explicit
cursor, or a searched update or
delete */
ulint *clust_map; /*!< map telling how clust_ref is built
from the fields of a non-clustered
record */
dtuple_t *clust_ref; /*!< the reference to the clustered
index entry is built here if index is
a non-clustered index */
btr_pcur_t clust_pcur; /*!< if index is non-clustered, we use
this pcur to search the clustered
index */
mem_heap_t *old_vers_heap; /*!< memory heap used in building an old
version of a row, or NULL */
};
/** Select node states */
enum sel_node_state {
SEL_NODE_CLOSED, /*!< it is a declared cursor which is not
currently open */
SEL_NODE_OPEN, /*!< intention locks not yet set on tables */
SEL_NODE_FETCH, /*!< intention locks have been set */
SEL_NODE_NO_MORE_ROWS /*!< cursor has reached the result set end */
};
/** Select statement node */
struct sel_node_t {
que_common_t common; /*!< node type: QUE_NODE_SELECT */
enum sel_node_state state; /*!< node state */
que_node_t *select_list; /*!< select list */
sym_node_t *into_list; /*!< variables list or NULL */
sym_node_t *table_list; /*!< table list */
ibool asc; /*!< TRUE if the rows should be fetched
in an ascending order */
ibool set_x_locks; /*!< TRUE if the cursor is for update or
delete, which means that a row x-lock
should be placed on the cursor row */
ulint row_lock_mode; /*!< LOCK_X or LOCK_S */
ulint n_tables; /*!< number of tables */
ulint fetch_table; /*!< number of the next table to access
in the join */
plan_t *plans; /*!< array of n_tables many plan nodes
containing the search plan and the
search data structures */
que_node_t *search_cond; /*!< search condition */
// ReadView *read_view;
lizard::Vision *vision;
/*!< if the query is a non-locking
consistent read, its read view is
placed here, otherwise NULL */
ibool consistent_read; /*!< TRUE if the select is a consistent,
non-locking read */
order_node_t *order_by; /*!< order by column definition, or
NULL */
ibool is_aggregate; /*!< TRUE if the select list consists of
aggregate functions */
ibool aggregate_already_fetched;
/*!< TRUE if the aggregate row has
already been fetched for the current
cursor */
ibool can_get_updated; /*!< this is TRUE if the select
is in a single-table explicit
cursor which can get updated
within the stored procedure,
or in a searched update or
delete; NOTE that to determine
of an explicit cursor if it
can get updated, the parser
checks from a stored procedure
if it contains positioned
update or delete statements */
sym_node_t *explicit_cursor; /*!< not NULL if an explicit cursor */
UT_LIST_BASE_NODE_T(sym_node_t)
copy_variables; /*!< variables whose values we have to
copy when an explicit cursor is opened,
so that they do not change between
fetches */
};
/** Fetch statement node */
struct fetch_node_t {
que_common_t common; /*!< type: QUE_NODE_FETCH */
sel_node_t *cursor_def; /*!< cursor definition */
sym_node_t *into_list; /*!< variables to set */
pars_user_func_t *func; /*!< User callback function or NULL.
The first argument to the function
is a sel_node_t*, containing the
results of the SELECT operation for
one row. If the function returns
NULL, it is not interested in
further rows and the cursor is
modified so (cursor % NOTFOUND) is
true. If it returns not-NULL,
continue normally. */
};
/** Open or close cursor operation type */
enum open_node_op {
ROW_SEL_OPEN_CURSOR, /*!< open cursor */
ROW_SEL_CLOSE_CURSOR /*!< close cursor */
};
/** Open or close cursor statement node */
struct open_node_t {
que_common_t common; /*!< type: QUE_NODE_OPEN */
enum open_node_op op_type; /*!< operation type: open or
close cursor */
sel_node_t *cursor_def; /*!< cursor definition */
};
/** Search direction for the MySQL interface */
enum row_sel_direction {
ROW_SEL_NEXT = 1, /*!< ascending direction */
ROW_SEL_PREV = 2 /*!< descending direction */
};
/** Match mode for the MySQL interface */
enum row_sel_match_mode {
ROW_SEL_EXACT = 1, /*!< search using a complete key value */
ROW_SEL_EXACT_PREFIX /*!< search using a key prefix which
must match rows: the prefix may
contain an incomplete field (the last
field in prefix may be just a prefix
of a fixed length column) */
};
#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 */
);
/** 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);
/** 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);
#include "row0sel.ic"
#endif