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FB8-172: Add variable to disable full table/index scans #970

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FB8-172: Add variable to disable full table/index scans #970

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4 changes: 4 additions & 0 deletions mysql-test/r/mysqld--help-notwin.result
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Expand Up @@ -705,6 +705,9 @@ The following options may be given as the first argument:
--optimizer-force-index-for-range
If enabled, FORCE INDEX will also try to force a range
plan.
--optimizer-full-scan
Enable full table and index scans.
(Defaults to on; use --skip-optimizer-full-scan to disable.)
--optimizer-prune-level=#
Controls the heuristic(s) applied during query
optimization to prune less-promising partial plans from
Expand Down Expand Up @@ -1598,6 +1601,7 @@ old FALSE
old-alter-table FALSE
old-style-user-limits FALSE
optimizer-force-index-for-range FALSE
optimizer-full-scan TRUE
optimizer-prune-level 1
optimizer-search-depth 62
optimizer-switch index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,engine_condition_pushdown=on,index_condition_pushdown=on,mrr=on,mrr_cost_based=on,block_nested_loop=on,batched_key_access=off,materialization=on,semijoin=on,loosescan=on,firstmatch=on,duplicateweedout=on,subquery_materialization_cost_based=on,use_index_extensions=on,condition_fanout_filter=on,derived_merge=on,use_invisible_indexes=off,skip_scan=on
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20 changes: 17 additions & 3 deletions mysql-test/r/opt_hints_set_var.result
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Expand Up @@ -473,18 +473,32 @@ id select_type table partitions type possible_keys key key_len ref rows filtered
1 SIMPLE t1 NULL index PRIMARY PRIMARY 4 NULL 4 100.00 Using index
Warnings:
Note 1003 /* select#1 */ select distinct `test`.`t1`.`a` AS `a` from `test`.`t1` FORCE INDEX (PRIMARY)
EXPLAIN SELECT /*+ SET_VAR(optimizer_force_index_for_range=1) */ DISTINCT a FROM t1 FORCE INDEX (PRIMARY);
EXPLAIN SELECT /*+ SET_VAR(optimizer_force_index_for_range=ON) */ DISTINCT a FROM t1 FORCE INDEX (PRIMARY);
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 NULL range PRIMARY PRIMARY 4 NULL 5 100.00 Using index for group-by
Warnings:
Note 1003 /* select#1 */ select /*+ SET_VAR(optimizer_force_index_for_range=1) */ distinct `test`.`t1`.`a` AS `a` from `test`.`t1` FORCE INDEX (PRIMARY)
CALL test_hint("SET_VAR(optimizer_force_index_for_range=1)", "optimizer_force_index_for_range");
Note 1003 /* select#1 */ select /*+ SET_VAR(optimizer_force_index_for_range='ON') */ distinct `test`.`t1`.`a` AS `a` from `test`.`t1` FORCE INDEX (PRIMARY)
EXPLAIN SELECT a FROM t1 IGNORE INDEX (PRIMARY) WHERE a IN (1, 2, 3) AND b IN (10, 20);
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 NULL ALL NULL NULL NULL NULL 4 25.00 Using where
Warnings:
Note 1003 /* select#1 */ select `test`.`t1`.`a` AS `a` from `test`.`t1` IGNORE INDEX (PRIMARY) where ((`test`.`t1`.`a` in (1,2,3)) and (`test`.`t1`.`b` in (10,20)))
SELECT /*+ SET_VAR(optimizer_full_scan=OFF) */ a FROM t1 IGNORE INDEX (PRIMARY) WHERE a IN (1, 2, 3) AND b IN (10, 20);
ERROR HY000: Full table/index scan is disabled
CALL test_hint("SET_VAR(optimizer_force_index_for_range=ON)", "optimizer_force_index_for_range");
VARIABLE_VALUE
OFF
VARIABLE_VALUE
ON
VARIABLE_VALUE
OFF
CALL test_hint("SET_VAR(optimizer_full_scan=OFF)", "optimizer_full_scan");
VARIABLE_VALUE
ON
VARIABLE_VALUE
OFF
VARIABLE_VALUE
ON
DROP TABLE t1, t2, t3;
CREATE TABLE t1
(
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116 changes: 116 additions & 0 deletions mysql-test/r/optimizer_full_scan.result
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@@ -0,0 +1,116 @@
CREATE TABLE t (i INT, j INT, KEY(i));
INSERT INTO t VALUES (1, 1);
INSERT INTO t VALUES (1, 2);
INSERT INTO t VALUES (2, 1);
INSERT INTO t VALUES (2, 2);
INSERT INTO t VALUES (3, 1);
INSERT INTO t VALUES (3, 2);
ANALYZE TABLE t;
Table Op Msg_type Msg_text
test.t analyze status OK
# Basic tests
EXPLAIN SELECT * FROM t;
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t NULL ALL NULL NULL NULL NULL # 100.00 NULL
Warnings:
Note 1003 /* select#1 */ select `test`.`t`.`i` AS `i`,`test`.`t`.`j` AS `j` from `test`.`t`
SET optimizer_full_scan = OFF;
SELECT * FROM t;
ERROR HY000: Full table/index scan is disabled
SET optimizer_full_scan = ON;
SELECT * FROM t;
i j
1 1
1 2
2 1
2 2
3 1
3 2
EXPLAIN SELECT i FROM t FORCE INDEX (i);
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t NULL index NULL i 5 NULL # 100.00 Using index
Warnings:
Note 1003 /* select#1 */ select `test`.`t`.`i` AS `i` from `test`.`t` FORCE INDEX (`i`)
SET optimizer_full_scan = OFF;
SELECT i FROM t FORCE INDEX (i);
ERROR HY000: Full table/index scan is disabled
SET optimizer_full_scan = ON;
SELECT i FROM t FORCE INDEX (i);
i
1
1
2
2
3
3
EXPLAIN SELECT * FROM t a, t b WHERE a.i = b.i;
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE a NULL ALL i NULL NULL NULL # 100.00 NULL
1 SIMPLE b NULL ALL i NULL NULL NULL # 33.33 Using where; Using join buffer (Block Nested Loop)
Warnings:
Note 1003 /* select#1 */ select `test`.`a`.`i` AS `i`,`test`.`a`.`j` AS `j`,`test`.`b`.`i` AS `i`,`test`.`b`.`j` AS `j` from `test`.`t` `a` join `test`.`t` `b` where (`test`.`b`.`i` = `test`.`a`.`i`)
SET optimizer_full_scan = OFF;
SELECT * FROM t a, t b WHERE a.i = b.i;
ERROR HY000: Full table/index scan is disabled
SET optimizer_full_scan = ON;
SELECT * FROM t a, t b WHERE a.i = b.i;
i j i j
1 1 1 1
1 2 1 1
1 1 1 2
1 2 1 2
2 1 2 1
2 2 2 1
2 1 2 2
2 2 2 2
3 1 3 1
3 2 3 1
3 1 3 2
3 2 3 2
EXPLAIN SELECT * FROM t a STRAIGHT_JOIN t b WHERE a.i = 10;
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE a NULL ref i i 5 const # 100.00 NULL
1 SIMPLE b NULL ALL NULL NULL NULL NULL # 100.00 Using join buffer (Block Nested Loop)
Warnings:
Note 1003 /* select#1 */ select `test`.`a`.`i` AS `i`,`test`.`a`.`j` AS `j`,`test`.`b`.`i` AS `i`,`test`.`b`.`j` AS `j` from `test`.`t` `a` straight_join `test`.`t` `b` where (`test`.`a`.`i` = 10)
SET optimizer_full_scan = OFF;
SELECT * FROM t a STRAIGHT_JOIN t b WHERE a.i = 10;
ERROR HY000: Full table/index scan is disabled
SET optimizer_full_scan = ON;
SELECT * FROM t a STRAIGHT_JOIN t b WHERE a.i = 10;
i j i j
SET @sql_mode_session = @@session.sql_mode;
SET SESSION sql_mode = '';
EXPLAIN SELECT * FROM (SELECT * FROM t GROUP BY i) a GROUP BY i;
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 PRIMARY <derived2> NULL ALL NULL NULL NULL NULL # 100.00 Using temporary
2 DERIVED t NULL index i i 5 NULL # 100.00 NULL
Warnings:
Note 1003 /* select#1 */ select `a`.`i` AS `i`,`a`.`j` AS `j` from (/* select#2 */ select `test`.`t`.`i` AS `i`,`test`.`t`.`j` AS `j` from `test`.`t` group by `test`.`t`.`i`) `a` group by `a`.`i`
SET SESSION sql_mode = @sql_mode_session;
# Test integration with optimizer_force_index_for_range
ALTER TABLE t DROP INDEX i, ADD PRIMARY KEY (i, j);
# Test range plans
SET optimizer_force_index_for_range = ON;
SET optimizer_full_scan = OFF;
EXPLAIN SELECT i FROM t WHERE i IN (1, 2, 3) AND j IN (1, 2);
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t NULL index PRIMARY PRIMARY 8 NULL # 100.00 Using where; Using index
Warnings:
Note 1003 /* select#1 */ select `test`.`t`.`i` AS `i` from `test`.`t` where ((`test`.`t`.`i` in (1,2,3)) and (`test`.`t`.`j` in (1,2)))
SELECT i FROM t WHERE i IN (1, 2, 3) AND j IN (1, 2);
ERROR HY000: Full table/index scan is disabled
EXPLAIN SELECT i FROM t FORCE INDEX (PRIMARY) WHERE i IN (1, 2, 3) AND j IN (1, 2);
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t NULL range PRIMARY PRIMARY 8 NULL # 100.00 Using where; Using index
Warnings:
Note 1003 /* select#1 */ select `test`.`t`.`i` AS `i` from `test`.`t` FORCE INDEX (PRIMARY) where ((`test`.`t`.`i` in (1,2,3)) and (`test`.`t`.`j` in (1,2)))
SELECT i FROM t FORCE INDEX (PRIMARY) WHERE i IN (1, 2, 3) AND j IN (1, 2);
i
1
1
2
2
3
3
DROP TABLE t;
93 changes: 93 additions & 0 deletions mysql-test/suite/sys_vars/r/optimizer_full_scan_basic.result
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@@ -0,0 +1,93 @@
SET @session_start_value = @@session.optimizer_full_scan;
SELECT @session_start_value;
@session_start_value
1
SET @global_start_value = @@global.optimizer_full_scan;
SELECT @global_start_value;
@global_start_value
1
SET @@session.optimizer_full_scan = 0;
SET @@session.optimizer_full_scan = DEFAULT;
SELECT @@session.optimizer_full_scan;
@@session.optimizer_full_scan
1
SET @@session.optimizer_full_scan = 1;
SET @@session.optimizer_full_scan = DEFAULT;
SELECT @@session.optimizer_full_scan;
@@session.optimizer_full_scan
1
SET optimizer_full_scan = 1;
SELECT @@optimizer_full_scan;
@@optimizer_full_scan
1
SELECT session.optimizer_full_scan;
ERROR 42S02: Unknown table 'session' in field list
SELECT local.optimizer_full_scan;
ERROR 42S02: Unknown table 'local' in field list
SET session optimizer_full_scan = 0;
SELECT @@session.optimizer_full_scan;
@@session.optimizer_full_scan
0
SET @@session.optimizer_full_scan = 0;
SELECT @@session.optimizer_full_scan;
@@session.optimizer_full_scan
0
SET @@session.optimizer_full_scan = 1;
SELECT @@session.optimizer_full_scan;
@@session.optimizer_full_scan
1
SET @@session.optimizer_full_scan = -1;
ERROR 42000: Variable 'optimizer_full_scan' can't be set to the value of '-1'
SET @@session.optimizer_full_scan = 2;
ERROR 42000: Variable 'optimizer_full_scan' can't be set to the value of '2'
SET @@session.optimizer_full_scan = "T";
ERROR 42000: Variable 'optimizer_full_scan' can't be set to the value of 'T'
SET @@session.optimizer_full_scan = "Y";
ERROR 42000: Variable 'optimizer_full_scan' can't be set to the value of 'Y'
SET @@session.optimizer_full_scan = NO;
ERROR 42000: Variable 'optimizer_full_scan' can't be set to the value of 'NO'
SET @@global.optimizer_full_scan = 1;
SELECT @@global.optimizer_full_scan;
@@global.optimizer_full_scan
1
SET @@global.optimizer_full_scan = 0;
SELECT count(VARIABLE_VALUE) FROM performance_schema.global_variables WHERE VARIABLE_NAME='optimizer_full_scan';
count(VARIABLE_VALUE)
1
SELECT IF(@@session.optimizer_full_scan, "ON", "OFF") = VARIABLE_VALUE
FROM performance_schema.session_variables
WHERE VARIABLE_NAME='optimizer_full_scan';
IF(@@session.optimizer_full_scan, "ON", "OFF") = VARIABLE_VALUE
1
SELECT @@session.optimizer_full_scan;
@@session.optimizer_full_scan
1
SELECT VARIABLE_VALUE
FROM performance_schema.session_variables
WHERE VARIABLE_NAME='optimizer_full_scan';
VARIABLE_VALUE
ON
SET @@session.optimizer_full_scan = OFF;
SELECT @@session.optimizer_full_scan;
@@session.optimizer_full_scan
0
SET @@session.optimizer_full_scan = ON;
SELECT @@session.optimizer_full_scan;
@@session.optimizer_full_scan
1
SET @@session.optimizer_full_scan = TRUE;
SELECT @@session.optimizer_full_scan;
@@session.optimizer_full_scan
1
SET @@session.optimizer_full_scan = FALSE;
SELECT @@session.optimizer_full_scan;
@@session.optimizer_full_scan
0
SET @@session.optimizer_full_scan = @session_start_value;
SELECT @@session.optimizer_full_scan;
@@session.optimizer_full_scan
1
SET @@global.optimizer_full_scan = @global_start_value;
SELECT @@global.optimizer_full_scan;
@@global.optimizer_full_scan
1
102 changes: 102 additions & 0 deletions mysql-test/suite/sys_vars/t/optimizer_full_scan_basic.test
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--source include/load_sysvars.inc


# Saving initial value of optimizer_full_scan in a temporary variable

SET @session_start_value = @@session.optimizer_full_scan;
SELECT @session_start_value;
SET @global_start_value = @@global.optimizer_full_scan;
SELECT @global_start_value;

# Display the DEFAULT value of optimizer_full_scan

SET @@session.optimizer_full_scan = 0;
SET @@session.optimizer_full_scan = DEFAULT;
SELECT @@session.optimizer_full_scan;

SET @@session.optimizer_full_scan = 1;
SET @@session.optimizer_full_scan = DEFAULT;
SELECT @@session.optimizer_full_scan;


# Check if optimizer_full_scan can be accessed with and without @@ sign

SET optimizer_full_scan = 1;
SELECT @@optimizer_full_scan;

--Error ER_UNKNOWN_TABLE
SELECT session.optimizer_full_scan;

--Error ER_UNKNOWN_TABLE
SELECT local.optimizer_full_scan;

SET session optimizer_full_scan = 0;
SELECT @@session.optimizer_full_scan;

# change the value of optimizer_full_scan to a valid value

SET @@session.optimizer_full_scan = 0;
SELECT @@session.optimizer_full_scan;
SET @@session.optimizer_full_scan = 1;
SELECT @@session.optimizer_full_scan;


# Change the value of optimizer_full_scan to invalid value

--Error ER_WRONG_VALUE_FOR_VAR
SET @@session.optimizer_full_scan = -1;
--Error ER_WRONG_VALUE_FOR_VAR
SET @@session.optimizer_full_scan = 2;
--Error ER_WRONG_VALUE_FOR_VAR
SET @@session.optimizer_full_scan = "T";
--Error ER_WRONG_VALUE_FOR_VAR
SET @@session.optimizer_full_scan = "Y";
--Error ER_WRONG_VALUE_FOR_VAR
SET @@session.optimizer_full_scan = NO;


# Test if accessing global optimizer_full_scan gives error

SET @@global.optimizer_full_scan = 1;
SELECT @@global.optimizer_full_scan;
SET @@global.optimizer_full_scan = 0;


# Check if the value in GLOBAL Table contains variable value

SELECT count(VARIABLE_VALUE) FROM performance_schema.global_variables WHERE VARIABLE_NAME='optimizer_full_scan';


# Check if the value in GLOBAL Table matches value in variable

SELECT IF(@@session.optimizer_full_scan, "ON", "OFF") = VARIABLE_VALUE
FROM performance_schema.session_variables
WHERE VARIABLE_NAME='optimizer_full_scan';
SELECT @@session.optimizer_full_scan;
SELECT VARIABLE_VALUE
FROM performance_schema.session_variables
WHERE VARIABLE_NAME='optimizer_full_scan';


# Check if ON and OFF values can be used on variable

SET @@session.optimizer_full_scan = OFF;
SELECT @@session.optimizer_full_scan;
SET @@session.optimizer_full_scan = ON;
SELECT @@session.optimizer_full_scan;


# Check if TRUE and FALSE values can be used on variable

SET @@session.optimizer_full_scan = TRUE;
SELECT @@session.optimizer_full_scan;
SET @@session.optimizer_full_scan = FALSE;
SELECT @@session.optimizer_full_scan;


# Restore initial value

SET @@session.optimizer_full_scan = @session_start_value;
SELECT @@session.optimizer_full_scan;
SET @@global.optimizer_full_scan = @global_start_value;
SELECT @@global.optimizer_full_scan;
12 changes: 9 additions & 3 deletions mysql-test/t/opt_hints_set_var.test
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Expand Up @@ -257,12 +257,18 @@ t2.a IN (SELECT t3.b FROM t3 JOIN t1 t4 ON t3.b = t4.b);
CALL test_hint("SET_VAR(optimizer_search_depth=1)", "optimizer_search_depth");
CALL test_hint("SET_VAR(optimizer_prune_level=0)", "optimizer_prune_level");

# Testing optimizer_force_index_for_range variable
# Testing optimizer_force_index_for_range, optimizer_full_scan variables
EXPLAIN SELECT DISTINCT a FROM t1 FORCE INDEX (PRIMARY);

EXPLAIN SELECT /*+ SET_VAR(optimizer_force_index_for_range=1) */ DISTINCT a FROM t1 FORCE INDEX (PRIMARY);
EXPLAIN SELECT /*+ SET_VAR(optimizer_force_index_for_range=ON) */ DISTINCT a FROM t1 FORCE INDEX (PRIMARY);

CALL test_hint("SET_VAR(optimizer_force_index_for_range=1)", "optimizer_force_index_for_range");
EXPLAIN SELECT a FROM t1 IGNORE INDEX (PRIMARY) WHERE a IN (1, 2, 3) AND b IN (10, 20);

--error ER_FULL_SCAN_DISABLED
SELECT /*+ SET_VAR(optimizer_full_scan=OFF) */ a FROM t1 IGNORE INDEX (PRIMARY) WHERE a IN (1, 2, 3) AND b IN (10, 20);

CALL test_hint("SET_VAR(optimizer_force_index_for_range=ON)", "optimizer_force_index_for_range");
CALL test_hint("SET_VAR(optimizer_full_scan=OFF)", "optimizer_full_scan");

DROP TABLE t1, t2, t3;

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