MDEV-19245: Impossible WHERE should be noticed earlier after HAVING pushdownbb-10.4-galina

The bug appears because not all conditions are found to be knowingly
true or false in WHERE after HAVING pushdown optimization.
Impossible WHERE can be found much earlier compared with how it is done now.

To fix it and_new_conditions_to_optimized_cond() is changed.

1 files changed, 43 insertions, 0 deletions

diff --git a/mysql-test/main/having_cond_pushdown.result b/mysql-test/main/having_cond_pushdown.result
index d7c9d936627..82a4813b156 100644
--- a/mysql-test/main/having_cond_pushdown.result
+++ b/mysql-test/main/having_cond_pushdown.result
@@ -4733,3 +4733,46 @@ EXPLAIN
   }
 }
 drop table t1;
+#
+# MDEV-19245: Impossible WHERE should be noticed earlier
+#             after HAVING pushdown
+#
+CREATE TABLE t1 (a INT, b INT, c INT);
+INSERT INTO t1 VALUES (1,2,1),(3,2,2),(5,6,4),(3,4,1);
+EXPLAIN SELECT t1.a,MAX(t1.b) FROM t1
+WHERE t1.a > 3 GROUP BY t1.a HAVING t1.a = 3;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+EXPLAIN SELECT t1.a,MAX(t1.b) FROM t1
+WHERE t1.a = 3 GROUP BY t1.a HAVING t1.a > 3;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+EXPLAIN SELECT t1.a,MAX(t1.b) FROM t1
+WHERE t1.a > 3 AND t1.a = 3 GROUP BY t1.a ;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+EXPLAIN SELECT t1.a,MAX(t1.b) FROM t1
+WHERE (t1.a < 2 OR t1.c > 1) GROUP BY t1.a HAVING t1.a = 3;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	4	Using where
+EXPLAIN SELECT t1.a,MAX(t1.b) FROM t1
+WHERE t1.a = 3 GROUP BY t1.a HAVING (t1.a < 2 OR t1.a > 3);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+EXPLAIN SELECT t1.a,MAX(t1.b) FROM t1
+WHERE t1.a = 3 AND (t1.a < 2 OR t1.a > 3) GROUP BY t1.a;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+EXPLAIN SELECT t1.a,MAX(t1.b),t1.c FROM t1
+WHERE (t1.a < 2 AND t1.c > 1) GROUP BY t1.a HAVING t1.a = 3;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+EXPLAIN SELECT t1.a,MAX(t1.b),t1.c FROM t1
+WHERE t1.a = 3 GROUP BY t1.a HAVING (t1.a < 2 AND t1.c > 1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+EXPLAIN SELECT t1.a,MAX(t1.b),t1.c FROM t1
+WHERE t1.a = 3 AND (t1.a < 2 AND t1.b > 3) GROUP BY t1.a;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+DROP TABLE t1;