Merge 10.3 into 10.4, except for MDEV-20265

The MDEV-20265 commit e746f451d57def4be679caafc29976741b3e89f7
introduces DBUG_ASSERT(right_op == r_tbl) in
st_select_lex::add_cross_joined_table(), and that assertion would
fail in several tests that exercise joins. That commit was skipped
in this merge, and a separate fix of MDEV-20265 will be necessary in 10.4.

1 files changed, 34 insertions, 0 deletions

diff --git a/mysql-test/main/selectivity_innodb.result b/mysql-test/main/selectivity_innodb.result
index 92091f0d6db..16f84ff3402 100644
--- a/mysql-test/main/selectivity_innodb.result
+++ b/mysql-test/main/selectivity_innodb.result
@@ -1647,6 +1647,40 @@ set @@use_stat_tables= @save_use_stat_tables;
 set @@optimizer_use_condition_selectivity=@save_optimizer_use_condition_selectivity;
 drop table t1;
 drop function f1;
+#
+# MDEV-19834 Selectivity of an equality condition discounted twice
+#
+set @@optimizer_use_condition_selectivity=4;
+set @@use_stat_tables='preferably';
+create table t1 (a int, b int, key (b), key (a));
+insert into t1
+select (rand(1)*1000)/10, (rand(1001)*1000)/50 from seq_1_to_1000;
+analyze table t1 ;
+Table	Op	Msg_type	Msg_text
+test.t1	analyze	status	Engine-independent statistics collected
+test.t1	analyze	status	OK
+# Check what info the optimizer has about selectivities
+explain extended select * from t1 use index () where a in (17,51,5);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	1000	3.90	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` USE INDEX () where `test`.`t1`.`a` in (17,51,5)
+explain extended select * from t1 use index () where b=2;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	1000	5.47	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` USE INDEX () where `test`.`t1`.`b` = 2
+# Now, the equality is used for ref access, while the range condition
+# gives selectivity data
+explain extended select * from t1 where a in (17,51,5) and b=2;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ref|filter	b,a	b|a	5|5	const	59 (3%)	2.90	Using where; Using rowid filter
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` where `test`.`t1`.`b` = 2 and `test`.`t1`.`a` in (17,51,5)
+drop table t1;
+set use_stat_tables= @save_use_stat_tables;
+set optimizer_use_condition_selectivity=@save_optimizer_use_condition_selectivity;
+# End of 10.1 tests
 set optimizer_switch=@save_optimizer_switch_for_selectivity_test;
 set @tmp_ust= @@use_stat_tables;
 set @tmp_oucs= @@optimizer_use_condition_selectivity;