Bug#31376809 PERFORMANCE REGRESSION FROM 5.7->8.0, DUE TO ANTIJOIN OF NOT EXISTS SUBQUERY

Disable antijoin transformation if this is:
- NOT EXISTS, or <constant> NOT IN,
- and the subquery is not correlated.
Otherwise we got this type of plan:
nested loop antijoin
   -> outer
   -> inner
and we would read each row of "outer", only to find, every time, that
there is a row in "inner" and that we should not emit the row of "outer".
Instead, we evaluate the subquery during optimization, leading to an always
true or false condition.
This does not cancel Steinar's patch for the same bug report; however it
makes "case 2" (see his commit comment) apply only to antijoin coming from
LEFT JOIN, as antijoin coming from NOT EXISTS will not reach the executor
anymore, due to the present patch.

Approved by: Roy Lyseng <[email protected]>

Change-Id: I59a887456a56039a6b1480b3ec8f7ac188d1ce58

Author: Guilhem Bichot

mysql-test/r/innodb_icp_all.result

@@ -715,14 +715,14 @@ AND 6=7
 )
 ;;
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t1a	NULL	ALL	NULL	NULL	NULL	NULL	1	100.00	NULL
-1	PRIMARY	t1b	NULL	ALL	NULL	NULL	NULL	NULL	1	100.00	Using where; Not exists; Using join buffer (hash join)
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	t1b	NULL	ALL	NULL	NULL	NULL	NULL	1	100.00	Using where
 3	DEPENDENT SUBQUERY	t2	NULL	unique_subquery	PRIMARY	PRIMARY	4	func	1	100.00	Using where; Full scan on NULL key
 Warnings:
 Note	1276	Field or reference 'test.t1b.t1_time' of SELECT #3 was resolved in SELECT #2
 Note	1276	Field or reference 'test.t1b.t1_int' of SELECT #3 was resolved in SELECT #2
 Note	1276	Field or reference 'test.t1b.t1_time' of SELECT #3 was resolved in SELECT #2
-Note	1003	/* select#1 */ select `test`.`t1a`.`t1_int` AS `t1_int`,`test`.`t1a`.`t1_time` AS `t1_time` from `test`.`t1` `t1a` anti join (`test`.`t1` `t1b`) on((<in_optimizer>(`test`.`t1b`.`t1_int`,<exists>(<primary_index_lookup>(<cache>(`test`.`t1b`.`t1_int`) in t2 on PRIMARY where ((`test`.`t1b`.`t1_time` like `test`.`t1b`.`t1_int`) and <if>(outer_field_is_not_null, (<cache>(`test`.`t1b`.`t1_int`) = `test`.`t2`.`t2_int`), true)))) is false))) where true
+Note	1003	/* select#1 */ select `test`.`t1a`.`t1_int` AS `t1_int`,`test`.`t1a`.`t1_time` AS `t1_time` from `test`.`t1` `t1a` where false
 
 DROP TABLE t1,t2;
 #

mysql-test/r/myisam_icp_all.result

@@ -713,14 +713,14 @@ AND 6=7
 )
 ;;
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t1a	NULL	system	NULL	NULL	NULL	NULL	1	100.00	NULL
-1	PRIMARY	t1b	NULL	ALL	NULL	NULL	NULL	NULL	1	100.00	Using where; Not exists
-3	DEPENDENT SUBQUERY	t2	NULL	system	PRIMARY	NULL	NULL	NULL	1	100.00	NULL
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	t1b	NULL	system	NULL	NULL	NULL	NULL	1	100.00	NULL
+3	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
 Warnings:
 Note	1276	Field or reference 'test.t1b.t1_time' of SELECT #3 was resolved in SELECT #2
 Note	1276	Field or reference 'test.t1b.t1_int' of SELECT #3 was resolved in SELECT #2
 Note	1276	Field or reference 'test.t1b.t1_time' of SELECT #3 was resolved in SELECT #2
-Note	1003	/* select#1 */ select NULL AS `t1_int`,NULL AS `t1_time` from <constant table> anti join (`test`.`t1` `t1b`) on((<in_optimizer>(`test`.`t1b`.`t1_int`,<exists>(/* select#3 */ select '0' from dual where ((`test`.`t1b`.`t1_time` like `test`.`t1b`.`t1_int`) and <if>(outer_field_is_not_null, (<cache>(`test`.`t1b`.`t1_int`) = '0'), true))) is false))) where true
+Note	1003	/* select#1 */ select `test`.`t1a`.`t1_int` AS `t1_int`,`test`.`t1a`.`t1_time` AS `t1_time` from `test`.`t1` `t1a` where false
 
 DROP TABLE t1,t2;
 #

mysql-test/r/subquery_all.result

@@ -5335,12 +5335,12 @@ SELECT COUNT(*) FROM t1
 WHERE NOT EXISTS (SELECT 1 FROM t2 WHERE 1 = (SELECT MIN(t2.b) FROM t3))
 ORDER BY COUNT(*);
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t1	NULL	index	NULL	a	5	NULL	2	100.00	Using index
-1	PRIMARY	t2	NULL	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Not exists; Using join buffer (hash join)
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
+2	SUBQUERY	t2	NULL	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 3	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 Warnings:
 Note	1276	Field or reference 'test.t2.b' of SELECT #3 was resolved in SELECT #2
-Note	1003	/* select#1 */ select count(0) AS `COUNT(*)` from `test`.`t1` anti join (`test`.`t2`) on(((1 = (/* select#3 */ select min(`test`.`t2`.`b`) from `test`.`t3`)))) where true
+Note	1003	/* select#1 */ select count(0) AS `COUNT(*)` from `test`.`t1` where true
 # should not crash the next statement
 SELECT COUNT(*) FROM t1
 WHERE NOT EXISTS (SELECT 1 FROM t2 WHERE 1 = (SELECT MIN(t2.b) FROM t3))

mysql-test/r/subquery_all_bka.result

@@ -5336,12 +5336,12 @@ SELECT COUNT(*) FROM t1
 WHERE NOT EXISTS (SELECT 1 FROM t2 WHERE 1 = (SELECT MIN(t2.b) FROM t3))
 ORDER BY COUNT(*);
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t1	NULL	index	NULL	a	5	NULL	2	100.00	Using index
-1	PRIMARY	t2	NULL	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Not exists; Using join buffer (hash join)
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
+2	SUBQUERY	t2	NULL	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 3	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 Warnings:
 Note	1276	Field or reference 'test.t2.b' of SELECT #3 was resolved in SELECT #2
-Note	1003	/* select#1 */ select count(0) AS `COUNT(*)` from `test`.`t1` anti join (`test`.`t2`) on(((1 = (/* select#3 */ select min(`test`.`t2`.`b`) from `test`.`t3`)))) where true
+Note	1003	/* select#1 */ select count(0) AS `COUNT(*)` from `test`.`t1` where true
 # should not crash the next statement
 SELECT COUNT(*) FROM t1
 WHERE NOT EXISTS (SELECT 1 FROM t2 WHERE 1 = (SELECT MIN(t2.b) FROM t3))

mysql-test/r/subquery_all_bka_nobnl.result

@@ -5336,12 +5336,12 @@ SELECT COUNT(*) FROM t1
 WHERE NOT EXISTS (SELECT 1 FROM t2 WHERE 1 = (SELECT MIN(t2.b) FROM t3))
 ORDER BY COUNT(*);
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t1	NULL	index	NULL	a	5	NULL	2	100.00	Using index
-1	PRIMARY	t2	NULL	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Not exists
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
+2	SUBQUERY	t2	NULL	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 3	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 Warnings:
 Note	1276	Field or reference 'test.t2.b' of SELECT #3 was resolved in SELECT #2
-Note	1003	/* select#1 */ select count(0) AS `COUNT(*)` from `test`.`t1` anti join (`test`.`t2`) on(((1 = (/* select#3 */ select min(`test`.`t2`.`b`) from `test`.`t3`)))) where true
+Note	1003	/* select#1 */ select count(0) AS `COUNT(*)` from `test`.`t1` where true
 # should not crash the next statement
 SELECT COUNT(*) FROM t1
 WHERE NOT EXISTS (SELECT 1 FROM t2 WHERE 1 = (SELECT MIN(t2.b) FROM t3))

mysql-test/r/subquery_antijoin.result

@@ -41,10 +41,10 @@ a
 EXPLAIN SELECT 1 as a FROM t2 as ot
 WHERE NOT EXISTS (SELECT * FROM t1 AS it);
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	ot	NULL	index	NULL	PRIMARY	4	NULL	80	100.00	Using index
-1	SIMPLE	it	NULL	index	NULL	ukn	4	NULL	3	100.00	Using where; Not exists; Using index; Using join buffer (hash join)
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	it	NULL	index	NULL	ukn	4	NULL	3	100.00	Using index
 Warnings:
-Note	1003	/* select#1 */ select 1 AS `a` from `test`.`t2` `ot` anti join (`test`.`t1` `it`) on((1 = 1)) where true
+Note	1003	/* select#1 */ select 1 AS `a` from `test`.`t2` `ot` where false
 SELECT 1 as a FROM t2 as ot
 WHERE NOT EXISTS (SELECT * FROM t1 AS it);
 a
@@ -177,11 +177,10 @@ a
 EXPLAIN SELECT 1 as a FROM t2 as ot
 WHERE NOT EXISTS (SELECT * FROM t1 AS it);
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	ot	NULL	index	NULL	PRIMARY	4	NULL	80	100.00	Using index
-1	SIMPLE	<subquery2>	NULL	const	<auto_distinct_key>	<auto_distinct_key>	8	const	1	100.00	Using where; Not exists
-2	MATERIALIZED	it	NULL	index	NULL	ukn	4	NULL	3	100.00	Using where; Using index
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	it	NULL	index	NULL	ukn	4	NULL	3	100.00	Using index
 Warnings:
-Note	1003	/* select#1 */ select 1 AS `a` from `test`.`t2` `ot` anti join (`test`.`t1` `it`) on((1 = 1)) where true
+Note	1003	/* select#1 */ select 1 AS `a` from `test`.`t2` `ot` where false
 SELECT 1 as a FROM t2 as ot
 WHERE NOT EXISTS (SELECT * FROM t1 AS it);
 a
@@ -469,11 +468,10 @@ Warnings:
 Note	1003	/* select#1 */ select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` semi join (`test`.`t1` `t3`) where true
 EXPLAIN SELECT * FROM t1 WHERE NOT EXISTS(SELECT * FROM t1 t3);
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	t1	NULL	ALL	NULL	NULL	NULL	NULL	3	100.00	NULL
-1	SIMPLE	<subquery2>	NULL	const	<auto_distinct_key>	<auto_distinct_key>	8	const	1	100.00	Using where; Not exists
-2	MATERIALIZED	t3	NULL	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	t3	NULL	ALL	NULL	NULL	NULL	NULL	3	100.00	NULL
 Warnings:
-Note	1003	/* select#1 */ select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` anti join (`test`.`t1` `t3`) on((1 = 1)) where true
+Note	1003	/* select#1 */ select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` where false
 EXPLAIN SELECT * FROM t1 WHERE EXISTS(SELECT * FROM t1 t3) IS TRUE;
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	<subquery2>	NULL	const	<auto_distinct_key>	<auto_distinct_key>	8	const	1	100.00	NULL
@@ -483,11 +481,10 @@ Warnings:
 Note	1003	/* select#1 */ select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` semi join (`test`.`t1` `t3`) where true
 EXPLAIN SELECT * FROM t1 WHERE EXISTS(SELECT * FROM t1 t3) IS FALSE;
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	t1	NULL	ALL	NULL	NULL	NULL	NULL	3	100.00	NULL
-1	SIMPLE	<subquery2>	NULL	const	<auto_distinct_key>	<auto_distinct_key>	8	const	1	100.00	Using where; Not exists
-2	MATERIALIZED	t3	NULL	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	t3	NULL	ALL	NULL	NULL	NULL	NULL	3	100.00	NULL
 Warnings:
-Note	1003	/* select#1 */ select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` anti join (`test`.`t1` `t3`) on((1 = 1)) where true
+Note	1003	/* select#1 */ select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` where false
 EXPLAIN SELECT * FROM t1 WHERE EXISTS(SELECT * FROM t1 t3) IS UNKNOWN;
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
@@ -496,11 +493,10 @@ Warnings:
 Note	1003	/* select#1 */ select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` where false
 EXPLAIN SELECT * FROM t1 WHERE EXISTS(SELECT * FROM t1 t3) IS NOT TRUE;
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	t1	NULL	ALL	NULL	NULL	NULL	NULL	3	100.00	NULL
-1	SIMPLE	<subquery2>	NULL	const	<auto_distinct_key>	<auto_distinct_key>	8	const	1	100.00	Using where; Not exists
-2	MATERIALIZED	t3	NULL	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	t3	NULL	ALL	NULL	NULL	NULL	NULL	3	100.00	NULL
 Warnings:
-Note	1003	/* select#1 */ select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` anti join (`test`.`t1` `t3`) on((1 = 1)) where true
+Note	1003	/* select#1 */ select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` where false
 EXPLAIN SELECT * FROM t1 WHERE EXISTS(SELECT * FROM t1 t3) IS NOT FALSE;
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	<subquery2>	NULL	const	<auto_distinct_key>	<auto_distinct_key>	8	const	1	100.00	NULL
@@ -656,13 +652,12 @@ subquery2_t1.col_varchar_key >= '2'
    ) AND
 t1.pk IN (2);
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	t1	NULL	const	PRIMARY	PRIMARY	4	const	1	100.00	NULL
-1	SIMPLE	<subquery2>	NULL	const	<auto_distinct_key>	<auto_distinct_key>	8	const	1	100.00	Using where; Not exists
-2	MATERIALIZED	subquery2_t1	NULL	index	idx_cc_col_varchar_key	idx_cc_col_varchar_key	7	NULL	1	100.00	Using index
-2	MATERIALIZED	subquery2_t2	NULL	index	NULL	idx_cc_col_varchar_key	7	NULL	1	100.00	Using where; Using index; Using join buffer (hash join)
-2	MATERIALIZED	subquery2_t3	NULL	index	NULL	idx_cc_col_varchar_key	7	NULL	1	100.00	Using index; Using join buffer (hash join)
+1	PRIMARY	t1	NULL	const	PRIMARY	PRIMARY	4	const	1	100.00	NULL
+2	SUBQUERY	subquery2_t1	NULL	index	idx_cc_col_varchar_key	idx_cc_col_varchar_key	7	NULL	1	100.00	Using index
+2	SUBQUERY	subquery2_t2	NULL	index	NULL	idx_cc_col_varchar_key	7	NULL	1	100.00	Using where; Using index; Using join buffer (hash join)
+2	SUBQUERY	subquery2_t3	NULL	index	NULL	idx_cc_col_varchar_key	7	NULL	1	100.00	Using index; Using join buffer (hash join)
 Warnings:
-Note	1003	/* select#1 */ select /*+ NO_SEMIJOIN(@`select#2` FIRSTMATCH) */ 'a' AS `col_varchar_key` from `test`.`t1` anti join (`test`.`t2` `subquery2_t1` left join (`test`.`t1` `subquery2_t2` join `test`.`t1` `subquery2_t3`) on((true))) on((((`test`.`subquery2_t2`.`col_varchar_key` <> `test`.`subquery2_t1`.`col_varchar_key`) or (`test`.`subquery2_t1`.`col_varchar_key` >= '2')))) where true
+Note	1003	/* select#1 */ select /*+ NO_SEMIJOIN(@`select#2` FIRSTMATCH) */ 'a' AS `col_varchar_key` from `test`.`t1` where true
 SELECT col_varchar_key FROM t1
 WHERE NOT EXISTS
 (SELECT /*+ NO_SEMIJOIN(FIRSTMATCH) */
@@ -723,14 +718,14 @@ WHERE NOT EXISTS (SELECT pk FROM t1 AS sj1)
 ON alias3.pk = alias1.col_int AND
 NOT EXISTS (SELECT * FROM t1 AS sj2 WHERE (SELECT 1) IS NULL);
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	alias1	NULL	ALL	NULL	NULL	NULL	NULL	1	100.00	NULL
-1	SIMPLE	t1	NULL	index	NULL	PRIMARY	4	NULL	1	100.00	Using index
-1	SIMPLE	alias2	NULL	eq_ref	PRIMARY	PRIMARY	4	test.alias1.col_int	1	100.00	Using index
-1	SIMPLE	<subquery3>	NULL	const	<auto_distinct_key>	<auto_distinct_key>	8	const	1	100.00	Using where; Not exists
-3	MATERIALIZED	sj1	NULL	index	NULL	PRIMARY	4	NULL	1	100.00	Using where; Using index
+1	PRIMARY	alias1	NULL	ALL	NULL	NULL	NULL	NULL	1	100.00	NULL
+1	PRIMARY	t1	NULL	index	NULL	PRIMARY	4	NULL	1	100.00	Using where; Using index
+1	PRIMARY	alias2	NULL	eq_ref	PRIMARY	PRIMARY	4	test.alias1.col_int	1	100.00	Using index
+4	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+3	SUBQUERY	sj1	NULL	index	NULL	PRIMARY	4	NULL	1	100.00	Using index
 Warnings:
 Note	1249	Select 5 was reduced during optimization
-Note	1003	/* select#1 */ select `test`.`alias1`.`pk` AS `pk` from `test`.`t1` `alias1` left join (`test`.`t1` join `test`.`t1` `alias2` anti join (`test`.`t1` `sj1`) on(true)) on(((`test`.`alias2`.`pk` = `test`.`alias1`.`col_int`))) where true
+Note	1003	/* select#1 */ select `test`.`alias1`.`pk` AS `pk` from `test`.`t1` `alias1` left join (`test`.`t1` join `test`.`t1` `alias2`) on(((`test`.`alias2`.`pk` = `test`.`alias1`.`col_int`) and exists(/* select#4 */ select 1 from `test`.`t1` `sj2` where false) is false and exists(/* select#3 */ select `test`.`sj1`.`pk` from `test`.`t1` `sj1`) is false)) where true
 SELECT alias1.pk
 FROM t1 AS alias1 LEFT JOIN
 (SELECT alias2.*
@@ -905,25 +900,26 @@ NOT EXISTS ( SELECT * FROM t1 as t4);
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	NULL	ALL	NULL	NULL	NULL	NULL	1	100.00	NULL
 1	PRIMARY	t2	NULL	ALL	NULL	NULL	NULL	NULL	1	100.00	Using where
-1	PRIMARY	<subquery3>	NULL	const	<auto_distinct_key>	<auto_distinct_key>	8	const	1	100.00	Using where; Not exists
-3	MATERIALIZED	t4	NULL	index	NULL	PRIMARY	4	NULL	1	100.00	Using where; Using index
+3	SUBQUERY	t4	NULL	index	NULL	PRIMARY	4	NULL	1	100.00	Using index
 2	UNCACHEABLE SUBQUERY	t3	NULL	index	NULL	PRIMARY	4	NULL	1	100.00	Using index
 Warnings:
-Note	1003	/* select#1 */ select `test`.`t1`.`pk` AS `pk`,`test`.`t1`.`col_int` AS `col_int`,`test`.`t2`.`pk` AS `pk`,`test`.`t2`.`col_int` AS `col_int` from `test`.`t1` left join (`test`.`t1` `t2` anti join (`test`.`t1` `t4`) on((1 = 1))) on(((`test`.`t1`.`col_int` > (/* select#2 */ select (@`var`) from `test`.`t1` `t3`)) and true)) where true
+Note	1003	/* select#1 */ select `test`.`t1`.`pk` AS `pk`,`test`.`t1`.`col_int` AS `col_int`,`test`.`t2`.`pk` AS `pk`,`test`.`t2`.`col_int` AS `col_int` from `test`.`t1` left join `test`.`t1` `t2` on(((`test`.`t1`.`col_int` > (/* select#2 */ select (@`var`) from `test`.`t1` `t3`)) and exists(/* select#3 */ select 1 from `test`.`t1` `t4`) is false)) where true
 EXPLAIN FORMAT=TREE SELECT * FROM t1 LEFT JOIN t1 AS t2
 ON 1 AND t1.col_int > ( SELECT @var FROM t1 as t3 ) AND
 NOT EXISTS ( SELECT * FROM t1 as t4);
 EXPLAIN
--> Nested loop left join
+-> Nested loop left join  (cost=0.70 rows=1)
     -> Table scan on t1  (cost=0.35 rows=1)
-    -> Filter: (t1.col_int > (select #2))
-        -> Nested loop antijoin
-            -> Table scan on t2  (cost=0.35 rows=1)
-            -> Constant row from <subquery3>
-                -> Materialize with deduplication
-                    -> Index scan on t4 using PRIMARY  (cost=0.35 rows=1)
+    -> Filter: (exists(select #3) is false and ((t1.col_int > (select #2)) and exists(select #3) is false))  (cost=0.35 rows=1)
+        -> Table scan on t2  (cost=0.35 rows=1)
+        -> Select #3 (subquery in condition; run only once)
+            -> Limit: 1 row(s)
+                -> Index scan on t4 using PRIMARY  (cost=0.35 rows=1)
         -> Select #2 (subquery in condition; uncacheable)
             -> Index scan on t3 using PRIMARY  (cost=0.35 rows=1)
+        -> Select #3 (subquery in condition; run only once)
+            -> Limit: 1 row(s)
+                -> Index scan on t4 using PRIMARY  (cost=0.35 rows=1)
 
 SELECT * FROM t1 LEFT JOIN t1 AS t2
 ON 1 AND t1.col_int > ( SELECT @var FROM t1 as t3 ) AND
@@ -1010,11 +1006,12 @@ alias1.col_datetime_key AS field3
 FROM t1 AS alias1 LEFT JOIN t1 AS alias2
 ON NOT EXISTS ( SELECT * FROM t1 AS alias3 WHERE ( SELECT 1 FROM DUAL ) IS NULL );
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	alias1	NULL	ALL	NULL	NULL	NULL	NULL	2	100.00	NULL
-1	SIMPLE	alias2	NULL	index	NULL	idx_C_col_varchar_key	6	NULL	2	100.00	Using where; Using index; Using join buffer (hash join)
+1	PRIMARY	alias1	NULL	ALL	NULL	NULL	NULL	NULL	2	100.00	NULL
+1	PRIMARY	alias2	NULL	index	NULL	idx_C_col_varchar_key	6	NULL	2	100.00	Using where; Using index; Using join buffer (hash join)
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
 Warnings:
 Note	1249	Select 3 was reduced during optimization
-Note	1003	/* select#1 */ select `test`.`alias1`.`col_int` AS `field1`,`test`.`alias2`.`col_varchar_key` AS `field2`,`test`.`alias1`.`col_datetime_key` AS `field3` from `test`.`t1` `alias1` left join `test`.`t1` `alias2` on(true) where true
+Note	1003	/* select#1 */ select `test`.`alias1`.`col_int` AS `field1`,`test`.`alias2`.`col_varchar_key` AS `field2`,`test`.`alias1`.`col_datetime_key` AS `field3` from `test`.`t1` `alias1` left join `test`.`t1` `alias2` on(exists(/* select#2 */ select 1 from `test`.`t1` `alias3` where false) is false) where true
 SELECT alias1.col_int AS field1 , alias2.col_varchar_key AS field2 ,
 alias1.col_datetime_key AS field3
 FROM t1 AS alias1 LEFT JOIN t1 AS alias2
@@ -1081,3 +1078,21 @@ SELECT MAX(t1.a) FROM t1 WHERE a NOT IN (SELECT a FROM t2);
 MAX(t1.a)
 1
 DROP TABLE t1, t2;
+#
+# Bug#31376809 PERFORMANCE REGRESSION FROM 5.7->8.0, DUE TO ANTIJOIN OF NOT EXISTS SUBQUERY
+#
+create table t(a int, b int);
+insert into t values(1,1),(2,2),(3,3),(4,4),(5,5);
+explain format=tree select a from t where (not exists (select b from t));
+EXPLAIN
+-> Zero rows (Impossible WHERE)
+
+select a from t where (not exists (select b from t));
+a
+explain format=tree select a from t where 1 not in (select 1 from t);
+EXPLAIN
+-> Zero rows (Impossible WHERE)
+
+select a from t where 1 not in (select 1 from t);
+a
+drop table t;