555 lines
15 KiB
Plaintext
555 lines
15 KiB
Plaintext
select @@global.xengine_parallel_read_threads into @parallel_scan_saved;
|
|
set global xengine_parallel_read_threads=1;
|
|
set xengine_parallel_read_threads=1;
|
|
CREATE TABLE t_xengine(c1 INT NOT NULL PRIMARY KEY,
|
|
c2 INT NOT NULL,
|
|
c3 char(20),
|
|
KEY c3_idx(c3))ENGINE=XENGINE;
|
|
INSERT INTO t_xengine VALUES (1, 1, 'a'), (2,2,'a'), (3,3,'a');
|
|
ANALYZE TABLE t_xengine;
|
|
Table Op Msg_type Msg_text
|
|
test.t_xengine analyze status OK
|
|
CREATE TABLE t_innnodb(c1 INT NOT NULL PRIMARY KEY,
|
|
c2 INT NOT NULL DEFAULT 1,
|
|
c3 char(20),
|
|
KEY c3_idx(c3)) ENGINE=InnoDB;
|
|
INSERT INTO t_innnodb(c1) VALUES (1), (2);
|
|
ANALYZE TABLE t_innnodb;
|
|
Table Op Msg_type Msg_text
|
|
test.t_innnodb analyze status OK
|
|
EXPLAIN SELECT COUNT(*) FROM t_xengine;
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE t_xengine NULL index NULL c3_idx 81 NULL 3 100.00 Using index
|
|
Warnings:
|
|
Note 1003 /* select#1 */ select count(0) AS `COUNT(*)` from `test`.`t_xengine`
|
|
EXPLAIN SELECT COUNT(*) FROM t_innnodb;
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE t_innnodb NULL index NULL c3_idx 81 NULL 2 100.00 Using index
|
|
Warnings:
|
|
Note 1003 /* select#1 */ select count(0) AS `COUNT(*)` from `test`.`t_innnodb`
|
|
EXPLAIN SELECT COUNT(*) FROM t_innnodb, t_xengine;
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE t_innnodb NULL index NULL c3_idx 81 NULL 2 100.00 Using index
|
|
1 SIMPLE t_xengine NULL index NULL c3_idx 81 NULL 3 100.00 Using index
|
|
Warnings:
|
|
Note 1003 /* select#1 */ select count(0) AS `COUNT(*)` from `test`.`t_innnodb` join `test`.`t_xengine`
|
|
EXPLAIN SELECT MIN(c2), COUNT(*), MAX(c1) FROM t_xengine;
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE t_xengine NULL ALL NULL NULL NULL NULL 3 100.00 NULL
|
|
Warnings:
|
|
Note 1003 /* select#1 */ select min(`test`.`t_xengine`.`c2`) AS `MIN(c2)`,count(0) AS `COUNT(*)`,max(`test`.`t_xengine`.`c1`) AS `MAX(c1)` from `test`.`t_xengine`
|
|
EXPLAIN SELECT MIN(c3), COUNT(*) FROM t_xengine;
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE t_xengine NULL index NULL c3_idx 81 NULL 3 100.00 Using index
|
|
Warnings:
|
|
Note 1003 /* select#1 */ select min(`test`.`t_xengine`.`c3`) AS `MIN(c3)`,count(0) AS `COUNT(*)` from `test`.`t_xengine`
|
|
FLUSH STATUS;
|
|
SELECT COUNT(*) FROM t_xengine;
|
|
COUNT(*)
|
|
3
|
|
SHOW STATUS LIKE 'Handler_%';
|
|
Variable_name Value
|
|
Handler_commit 0
|
|
Handler_delete 0
|
|
Handler_discover 0
|
|
Handler_external_lock 2
|
|
Handler_mrr_init 0
|
|
Handler_prepare 0
|
|
Handler_read_first 1
|
|
Handler_read_key 0
|
|
Handler_read_last 0
|
|
Handler_read_next 3
|
|
Handler_read_prev 0
|
|
Handler_read_rnd 0
|
|
Handler_read_rnd_next 0
|
|
Handler_rollback 0
|
|
Handler_savepoint 0
|
|
Handler_savepoint_rollback 0
|
|
Handler_update 0
|
|
Handler_write 0
|
|
FLUSH STATUS;
|
|
SELECT COUNT(*) FROM t_innnodb;
|
|
COUNT(*)
|
|
2
|
|
SHOW STATUS LIKE 'Handler_%';
|
|
Variable_name Value
|
|
Handler_commit 1
|
|
Handler_delete 0
|
|
Handler_discover 0
|
|
Handler_external_lock 2
|
|
Handler_mrr_init 0
|
|
Handler_prepare 0
|
|
Handler_read_first 0
|
|
Handler_read_key 0
|
|
Handler_read_last 0
|
|
Handler_read_next 0
|
|
Handler_read_prev 0
|
|
Handler_read_rnd 0
|
|
Handler_read_rnd_next 0
|
|
Handler_rollback 0
|
|
Handler_savepoint 0
|
|
Handler_savepoint_rollback 0
|
|
Handler_update 0
|
|
Handler_write 0
|
|
FLUSH STATUS;
|
|
SELECT COUNT(*) FROM t_innnodb, t_xengine;
|
|
COUNT(*)
|
|
6
|
|
SHOW STATUS LIKE 'Handler_%';
|
|
Variable_name Value
|
|
Handler_commit 1
|
|
Handler_delete 0
|
|
Handler_discover 0
|
|
Handler_external_lock 4
|
|
Handler_mrr_init 0
|
|
Handler_prepare 0
|
|
Handler_read_first 1
|
|
Handler_read_key 0
|
|
Handler_read_last 0
|
|
Handler_read_next 3
|
|
Handler_read_prev 0
|
|
Handler_read_rnd 0
|
|
Handler_read_rnd_next 0
|
|
Handler_rollback 0
|
|
Handler_savepoint 0
|
|
Handler_savepoint_rollback 0
|
|
Handler_update 0
|
|
Handler_write 0
|
|
FLUSH STATUS;
|
|
SELECT MIN(c2), COUNT(*), MAX(c1) FROM t_xengine;
|
|
MIN(c2) COUNT(*) MAX(c1)
|
|
1 3 3
|
|
SHOW STATUS LIKE 'Handler_%';
|
|
Variable_name Value
|
|
Handler_commit 0
|
|
Handler_delete 0
|
|
Handler_discover 0
|
|
Handler_external_lock 2
|
|
Handler_mrr_init 0
|
|
Handler_prepare 0
|
|
Handler_read_first 0
|
|
Handler_read_key 0
|
|
Handler_read_last 1
|
|
Handler_read_next 0
|
|
Handler_read_prev 0
|
|
Handler_read_rnd 0
|
|
Handler_read_rnd_next 4
|
|
Handler_rollback 0
|
|
Handler_savepoint 0
|
|
Handler_savepoint_rollback 0
|
|
Handler_update 0
|
|
Handler_write 0
|
|
FLUSH STATUS;
|
|
SELECT MIN(c3), COUNT(*) FROM t_xengine;
|
|
MIN(c3) COUNT(*)
|
|
a 3
|
|
SHOW STATUS LIKE 'Handler_%';
|
|
Variable_name Value
|
|
Handler_commit 0
|
|
Handler_delete 0
|
|
Handler_discover 0
|
|
Handler_external_lock 2
|
|
Handler_mrr_init 0
|
|
Handler_prepare 0
|
|
Handler_read_first 1
|
|
Handler_read_key 1
|
|
Handler_read_last 0
|
|
Handler_read_next 3
|
|
Handler_read_prev 0
|
|
Handler_read_rnd 0
|
|
Handler_read_rnd_next 0
|
|
Handler_rollback 0
|
|
Handler_savepoint 0
|
|
Handler_savepoint_rollback 0
|
|
Handler_update 0
|
|
Handler_write 0
|
|
CREATE TABLE t_nopk(c1 INT NOT NULL , c2 INT NOT NULL)ENGINE=XENGINE;
|
|
INSERT INTO t_nopk SELECT c1, c2 FROM t_xengine;
|
|
SHOW CREATE TABLE t_nopk;
|
|
Table Create Table
|
|
t_nopk CREATE TABLE `t_nopk` (
|
|
`c1` int(11) NOT NULL,
|
|
`c2` int(11) NOT NULL
|
|
) ENGINE=XENGINE DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci
|
|
EXPLAIN SELECT COUNT(*) FROM t_nopk;
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE t_nopk NULL ALL NULL NULL NULL NULL # # NULL
|
|
Warnings:
|
|
Note 1003 /* select#1 */ select count(0) AS `COUNT(*)` from `test`.`t_nopk`
|
|
FLUSH STATUS;
|
|
SELECT COUNT(*) FROM t_nopk;
|
|
COUNT(*)
|
|
3
|
|
SHOW STATUS LIKE 'Handler_%';
|
|
Variable_name Value
|
|
Handler_commit 0
|
|
Handler_delete 0
|
|
Handler_discover 0
|
|
Handler_external_lock 2
|
|
Handler_mrr_init 0
|
|
Handler_prepare 0
|
|
Handler_read_first 0
|
|
Handler_read_key 0
|
|
Handler_read_last 0
|
|
Handler_read_next 0
|
|
Handler_read_prev 0
|
|
Handler_read_rnd 0
|
|
Handler_read_rnd_next 4
|
|
Handler_rollback 0
|
|
Handler_savepoint 0
|
|
Handler_savepoint_rollback 0
|
|
Handler_update 0
|
|
Handler_write 0
|
|
CREATE INDEX c2_idx on t_nopk(c2);
|
|
SHOW CREATE TABLE t_nopk;
|
|
Table Create Table
|
|
t_nopk CREATE TABLE `t_nopk` (
|
|
`c1` int(11) NOT NULL,
|
|
`c2` int(11) NOT NULL,
|
|
KEY `c2_idx` (`c2`)
|
|
) ENGINE=XENGINE DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci
|
|
EXPLAIN SELECT COUNT(*) FROM t_nopk;
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE t_nopk NULL index NULL c2_idx 4 NULL # # Using index
|
|
Warnings:
|
|
Note 1003 /* select#1 */ select count(0) AS `COUNT(*)` from `test`.`t_nopk`
|
|
FLUSH STATUS;
|
|
SELECT COUNT(*) FROM t_nopk;
|
|
COUNT(*)
|
|
3
|
|
SHOW STATUS LIKE 'Handler_%';
|
|
Variable_name Value
|
|
Handler_commit 0
|
|
Handler_delete 0
|
|
Handler_discover 0
|
|
Handler_external_lock 2
|
|
Handler_mrr_init 0
|
|
Handler_prepare 0
|
|
Handler_read_first 1
|
|
Handler_read_key 0
|
|
Handler_read_last 0
|
|
Handler_read_next 3
|
|
Handler_read_prev 0
|
|
Handler_read_rnd 0
|
|
Handler_read_rnd_next 0
|
|
Handler_rollback 0
|
|
Handler_savepoint 0
|
|
Handler_savepoint_rollback 0
|
|
Handler_update 0
|
|
Handler_write 0
|
|
DROP TABLE t_nopk;
|
|
CREATE TABLE t_xengine_nopk_sk(c1 INT NOT NULL,
|
|
c2 INT NOT NULL, KEY c2_idx(c2))ENGINE=XENGINE;
|
|
CREATE TABLE t_xengine_pk_nosk(c1 INT NOT NULL PRIMARY KEY,
|
|
c2 INT NOT NULL)ENGINE=XENGINE;
|
|
CREATE TABLE t_xengine_nopk_nosk(c1 INT NOT NULL,
|
|
c2 INT NOT NULL)ENGINE=XENGINE;
|
|
INSERT INTO t_xengine_nopk_sk(c1,c2) VALUES (1, 1), (2,2), (3,3);
|
|
INSERT INTO t_xengine_pk_nosk(c1,c2) SELECT * FROM t_xengine_nopk_sk;
|
|
INSERT INTO t_xengine_nopk_nosk(c1,c2) SELECT * FROM t_xengine_nopk_sk;
|
|
ANALYZE TABLE t_xengine_nopk_sk, t_xengine_pk_nosk, t_xengine_nopk_nosk;
|
|
Table Op Msg_type Msg_text
|
|
test.t_xengine_nopk_sk analyze status OK
|
|
test.t_xengine_pk_nosk analyze status OK
|
|
test.t_xengine_nopk_nosk analyze status OK
|
|
EXPLAIN SELECT COUNT(*) FROM t_xengine_nopk_sk;
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE t_xengine_nopk_sk NULL index NULL c2_idx 4 NULL # # Using index
|
|
Warnings:
|
|
Note 1003 /* select#1 */ select count(0) AS `COUNT(*)` from `test`.`t_xengine_nopk_sk`
|
|
EXPLAIN SELECT COUNT(*) FROM t_xengine_pk_nosk;
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE t_xengine_pk_nosk NULL index NULL PRIMARY 4 NULL # # Using index
|
|
Warnings:
|
|
Note 1003 /* select#1 */ select count(0) AS `COUNT(*)` from `test`.`t_xengine_pk_nosk`
|
|
EXPLAIN SELECT COUNT(*) FROM t_xengine_nopk_nosk;
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE t_xengine_nopk_nosk NULL ALL NULL NULL NULL NULL # # NULL
|
|
Warnings:
|
|
Note 1003 /* select#1 */ select count(0) AS `COUNT(*)` from `test`.`t_xengine_nopk_nosk`
|
|
FLUSH STATUS;
|
|
SELECT COUNT(*) FROM t_xengine_nopk_sk;
|
|
COUNT(*)
|
|
3
|
|
SHOW STATUS LIKE 'Handler_%';
|
|
Variable_name Value
|
|
Handler_commit 0
|
|
Handler_delete 0
|
|
Handler_discover 0
|
|
Handler_external_lock 2
|
|
Handler_mrr_init 0
|
|
Handler_prepare 0
|
|
Handler_read_first 1
|
|
Handler_read_key 0
|
|
Handler_read_last 0
|
|
Handler_read_next 3
|
|
Handler_read_prev 0
|
|
Handler_read_rnd 0
|
|
Handler_read_rnd_next 0
|
|
Handler_rollback 0
|
|
Handler_savepoint 0
|
|
Handler_savepoint_rollback 0
|
|
Handler_update 0
|
|
Handler_write 0
|
|
FLUSH STATUS;
|
|
SELECT COUNT(*) FROM t_xengine_pk_nosk;
|
|
COUNT(*)
|
|
3
|
|
SHOW STATUS LIKE 'Handler_%';
|
|
Variable_name Value
|
|
Handler_commit 0
|
|
Handler_delete 0
|
|
Handler_discover 0
|
|
Handler_external_lock 2
|
|
Handler_mrr_init 0
|
|
Handler_prepare 0
|
|
Handler_read_first 0
|
|
Handler_read_key 0
|
|
Handler_read_last 0
|
|
Handler_read_next 0
|
|
Handler_read_prev 0
|
|
Handler_read_rnd 0
|
|
Handler_read_rnd_next 4
|
|
Handler_rollback 0
|
|
Handler_savepoint 0
|
|
Handler_savepoint_rollback 0
|
|
Handler_update 0
|
|
Handler_write 0
|
|
FLUSH STATUS;
|
|
SELECT COUNT(*) FROM t_xengine_nopk_nosk;
|
|
COUNT(*)
|
|
3
|
|
SHOW STATUS LIKE 'Handler_%';
|
|
Variable_name Value
|
|
Handler_commit 0
|
|
Handler_delete 0
|
|
Handler_discover 0
|
|
Handler_external_lock 2
|
|
Handler_mrr_init 0
|
|
Handler_prepare 0
|
|
Handler_read_first 0
|
|
Handler_read_key 0
|
|
Handler_read_last 0
|
|
Handler_read_next 0
|
|
Handler_read_prev 0
|
|
Handler_read_rnd 0
|
|
Handler_read_rnd_next 4
|
|
Handler_rollback 0
|
|
Handler_savepoint 0
|
|
Handler_savepoint_rollback 0
|
|
Handler_update 0
|
|
Handler_write 0
|
|
DROP TABLE t_xengine_pk_nosk, t_xengine_nopk_sk, t_xengine_nopk_nosk;
|
|
CREATE TABLE t_heap(c1 INT NOT NULL PRIMARY KEY,
|
|
c2 INT NOT NULL,
|
|
c3 char(20)) ENGINE=HEAP;
|
|
CREATE TABLE t_archive(c1 INT NOT NULL, c2 char(20)) ENGINE=ARCHIVE;
|
|
INSERT INTO t_heap SELECT * FROM t_xengine WHERE c1 > 1;
|
|
INSERT INTO t_archive SELECT c1, c3 FROM t_xengine WHERE c1 > 1;
|
|
EXPLAIN SELECT COUNT(*) FROM t_heap;
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
|
|
Warnings:
|
|
Note 1003 /* select#1 */ select count(0) AS `COUNT(*)` from `test`.`t_heap`
|
|
EXPLAIN SELECT COUNT(*) FROM t_xengine, t_heap;
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE t_heap NULL ALL NULL NULL NULL NULL 2 100.00 NULL
|
|
1 SIMPLE t_xengine NULL index NULL c3_idx 81 NULL 3 100.00 Using index
|
|
Warnings:
|
|
Note 1003 /* select#1 */ select count(0) AS `COUNT(*)` from `test`.`t_xengine` join `test`.`t_heap`
|
|
EXPLAIN SELECT COUNT(*) FROM t_archive;
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
|
|
Warnings:
|
|
Note 1003 /* select#1 */ select count(0) AS `COUNT(*)` from `test`.`t_archive`
|
|
EXPLAIN SELECT COUNT(*) FROM t_xengine, t_archive;
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE t_archive NULL ALL NULL NULL NULL NULL 2 100.00 NULL
|
|
1 SIMPLE t_xengine NULL index NULL c3_idx 81 NULL 3 100.00 Using index
|
|
Warnings:
|
|
Note 1003 /* select#1 */ select count(0) AS `COUNT(*)` from `test`.`t_xengine` join `test`.`t_archive`
|
|
FLUSH STATUS;
|
|
SELECT COUNT(*) FROM t_heap;
|
|
COUNT(*)
|
|
2
|
|
SHOW STATUS LIKE 'Handler_%';
|
|
Variable_name Value
|
|
Handler_commit 0
|
|
Handler_delete 0
|
|
Handler_discover 0
|
|
Handler_external_lock 2
|
|
Handler_mrr_init 0
|
|
Handler_prepare 0
|
|
Handler_read_first 0
|
|
Handler_read_key 0
|
|
Handler_read_last 0
|
|
Handler_read_next 0
|
|
Handler_read_prev 0
|
|
Handler_read_rnd 0
|
|
Handler_read_rnd_next 0
|
|
Handler_rollback 0
|
|
Handler_savepoint 0
|
|
Handler_savepoint_rollback 0
|
|
Handler_update 0
|
|
Handler_write 0
|
|
FLUSH STATUS;
|
|
SELECT COUNT(*) FROM t_xengine, t_heap;
|
|
COUNT(*)
|
|
6
|
|
SHOW STATUS LIKE 'Handler_%';
|
|
Variable_name Value
|
|
Handler_commit 0
|
|
Handler_delete 0
|
|
Handler_discover 0
|
|
Handler_external_lock 4
|
|
Handler_mrr_init 0
|
|
Handler_prepare 0
|
|
Handler_read_first 1
|
|
Handler_read_key 0
|
|
Handler_read_last 0
|
|
Handler_read_next 3
|
|
Handler_read_prev 0
|
|
Handler_read_rnd 0
|
|
Handler_read_rnd_next 0
|
|
Handler_rollback 0
|
|
Handler_savepoint 0
|
|
Handler_savepoint_rollback 0
|
|
Handler_update 0
|
|
Handler_write 0
|
|
FLUSH STATUS;
|
|
SELECT COUNT(*) FROM t_archive;
|
|
COUNT(*)
|
|
2
|
|
SHOW STATUS LIKE 'Handler_%';
|
|
Variable_name Value
|
|
Handler_commit 0
|
|
Handler_delete 0
|
|
Handler_discover 0
|
|
Handler_external_lock 2
|
|
Handler_mrr_init 0
|
|
Handler_prepare 0
|
|
Handler_read_first 0
|
|
Handler_read_key 0
|
|
Handler_read_last 0
|
|
Handler_read_next 0
|
|
Handler_read_prev 0
|
|
Handler_read_rnd 0
|
|
Handler_read_rnd_next 0
|
|
Handler_rollback 0
|
|
Handler_savepoint 0
|
|
Handler_savepoint_rollback 0
|
|
Handler_update 0
|
|
Handler_write 0
|
|
FLUSH STATUS;
|
|
SELECT COUNT(*) FROM t_xengine, t_archive;
|
|
COUNT(*)
|
|
6
|
|
SHOW STATUS LIKE 'Handler_%';
|
|
Variable_name Value
|
|
Handler_commit 0
|
|
Handler_delete 0
|
|
Handler_discover 0
|
|
Handler_external_lock 4
|
|
Handler_mrr_init 0
|
|
Handler_prepare 0
|
|
Handler_read_first 1
|
|
Handler_read_key 0
|
|
Handler_read_last 0
|
|
Handler_read_next 3
|
|
Handler_read_prev 0
|
|
Handler_read_rnd 0
|
|
Handler_read_rnd_next 0
|
|
Handler_rollback 0
|
|
Handler_savepoint 0
|
|
Handler_savepoint_rollback 0
|
|
Handler_update 0
|
|
Handler_write 0
|
|
DROP TABLE t_archive, t_heap;
|
|
EXPLAIN SELECT COUNT(*) FROM t_xengine FORCE INDEX(c3_idx);
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE t_xengine NULL index NULL c3_idx 81 NULL 3 100.00 Using index
|
|
Warnings:
|
|
Note 1003 /* select#1 */ select count(0) AS `COUNT(*)` from `test`.`t_xengine` FORCE INDEX (`c3_idx`)
|
|
EXPLAIN SELECT COUNT(*) FROM t_innnodb FORCE INDEX(c3_idx);
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE t_innnodb NULL index NULL c3_idx 81 NULL 2 100.00 Using index
|
|
Warnings:
|
|
Note 1003 /* select#1 */ select count(0) AS `COUNT(*)` from `test`.`t_innnodb` FORCE INDEX (`c3_idx`)
|
|
FLUSH STATUS;
|
|
SELECT COUNT(*) FROM t_xengine FORCE INDEX(c3_idx);
|
|
COUNT(*)
|
|
3
|
|
SHOW STATUS LIKE 'Handler_%';
|
|
Variable_name Value
|
|
Handler_commit 0
|
|
Handler_delete 0
|
|
Handler_discover 0
|
|
Handler_external_lock 2
|
|
Handler_mrr_init 0
|
|
Handler_prepare 0
|
|
Handler_read_first 1
|
|
Handler_read_key 0
|
|
Handler_read_last 0
|
|
Handler_read_next 3
|
|
Handler_read_prev 0
|
|
Handler_read_rnd 0
|
|
Handler_read_rnd_next 0
|
|
Handler_rollback 0
|
|
Handler_savepoint 0
|
|
Handler_savepoint_rollback 0
|
|
Handler_update 0
|
|
Handler_write 0
|
|
FLUSH STATUS;
|
|
SELECT COUNT(*) FROM t_innnodb FORCE INDEX(c3_idx);
|
|
COUNT(*)
|
|
2
|
|
SHOW STATUS LIKE 'Handler_%';
|
|
Variable_name Value
|
|
Handler_commit 1
|
|
Handler_delete 0
|
|
Handler_discover 0
|
|
Handler_external_lock 2
|
|
Handler_mrr_init 0
|
|
Handler_prepare 0
|
|
Handler_read_first 0
|
|
Handler_read_key 0
|
|
Handler_read_last 0
|
|
Handler_read_next 0
|
|
Handler_read_prev 0
|
|
Handler_read_rnd 0
|
|
Handler_read_rnd_next 0
|
|
Handler_rollback 0
|
|
Handler_savepoint 0
|
|
Handler_savepoint_rollback 0
|
|
Handler_update 0
|
|
Handler_write 0
|
|
SELECT COUNT(*) FROM (SELECT DISTINCT c1 FROM t_innnodb) dt, t_innnodb;
|
|
COUNT(*)
|
|
4
|
|
SET @s =1;
|
|
SELECT @s, COUNT(*) FROM t_xengine;
|
|
@s COUNT(*)
|
|
1 3
|
|
set sql_mode='';
|
|
SELECT 1 AS c1, (SELECT COUNT(*) FROM t_xengine HAVING c1 > 0) FROM DUAL;
|
|
c1 (SELECT COUNT(*) FROM t_xengine HAVING c1 > 0)
|
|
1 3
|
|
SELECT 1 FROM t_xengine HAVING COUNT(*) > 1;
|
|
1
|
|
1
|
|
SELECT COUNT(*) c FROM t_xengine HAVING c > 1;
|
|
c
|
|
3
|
|
SELECT COUNT(*) c FROM t_xengine HAVING c > 7;
|
|
c
|
|
set sql_mode=default;
|
|
SELECT SQL_BIG_RESULT COUNT(*) FROM t_xengine;
|
|
COUNT(*)
|
|
3
|
|
SELECT SQL_BIG_RESULT COUNT(*) FROM t_xengine, t_innnodb;
|
|
COUNT(*)
|
|
6
|
|
DROP TABLE t_xengine, t_innnodb;
|
|
set xengine_parallel_read_threads=@parallel_scan_saved;
|
|
set global xengine_parallel_read_threads=@parallel_scan_saved;
|