Merge 10.2 into 10.3

1 files changed, 41 insertions, 0 deletions

diff --git a/mysql-test/main/range.result b/mysql-test/main/range.result
index 052ea09d5ac..464c0bf031a 100644
--- a/mysql-test/main/range.result
+++ b/mysql-test/main/range.result
@@ -2981,5 +2981,46 @@ deallocate prepare stmt;
 set optimizer_switch=@save_optimizer_switch;
 drop table t1,t2,t3;
 #
+# MDEV-16934: using system variable eq_range_index_dive_limit
+#             to reduce the number of index dives
+#
+create table t1 (a int, b varchar(31), index idx(a));
+insert into t1 values
+(7,'xxxx'), (1,'yy'), (3,'aaa'), (1,'bbb'), (2,'zz'),
+(4,'vvvvv'), (7,'ddd'), (9,'zzzzz'), (1,'cc'), (5,'ffff');
+insert into t1 select a+10, concat(b,'zz') from t1;
+insert into t1 select a+15, concat(b,'yy') from t1;
+insert into t1 select a+100, concat(b,'xx') from t1;
+analyze table t1;
+Table	Op	Msg_type	Msg_text
+test.t1	analyze	status	OK
+select cast(count(a)/count(distinct a) as unsigned) as rec_per_key from t1;
+rec_per_key
+2
+set eq_range_index_dive_limit=0;
+explain select * from t1 where a in (8, 15, 31, 1, 9);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	idx	idx	5	NULL	7	Using index condition
+select * from t1 where a in (8, 15, 31, 1, 9);
+a	b
+1	yy
+1	bbb
+1	cc
+9	zzzzz
+15	ffffzz
+set eq_range_index_dive_limit=2;
+explain select * from t1 where a in (8, 15, 31, 1, 9);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	idx	idx	5	NULL	10	Using index condition
+select * from t1 where a in (8, 15, 31, 1, 9);
+a	b
+1	yy
+1	bbb
+1	cc
+9	zzzzz
+15	ffffzz
+set eq_range_index_dive_limit=default;
+drop table t1;
+#
 # End of 10.2 tests
 #