[MDEV-33080] main.innodb_ext_key test case explain estimates 6 rows sometimes Created: 2023-12-20  Updated: 2024-01-22

Status: Open
Project: MariaDB Server
Component/s: Optimizer, Tests
Affects Version/s: 10.5
Fix Version/s: 10.5

Type: Bug Priority: Critical
Reporter: Daniel Black Assignee: Daniel Black
Resolution: Unresolved Votes: 0
Labels: not-10.4, not-10.6+

Issue Links:
Blocks
blocks MDEV-33073 always green buildbot Open
Relates
relates to MDEV-20169 main.partition_innodb fails in buildb... Closed

 Description   

failure affects projected branch builder amd64-ubuntu-2204-debug-ps

CURRENT_TEST: main.innodb_ext_key
--- /home/buildbot/amd64-debian-11-msan/build/mysql-test/main/innodb_ext_key.result	2023-09-19 15:43:25.000000000 +0000
+++ /home/buildbot/amd64-debian-11-msan/build/mysql-test/main/innodb_ext_key.reject	2023-09-19 16:04:24.374253623 +0000
@@ -314,7 +314,7 @@
 select * from t0, part ignore index (primary)
 where p_partkey=t0.a and p_size=1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t0	ALL	NULL	NULL	NULL	NULL	5	Using where
+1	SIMPLE	t0	ALL	NULL	NULL	NULL	NULL	6	Using where
 1	SIMPLE	part	eq_ref	i_p_size	i_p_size	9	const,dbt3_s001.t0.a	1	
 select * from t0,  part ignore index (primary)
 where p_partkey=t0.a and p_size=1;

The table has 5 rows in the test. 6 rows is an over estimate.

Non-10.5 branches have resolved tests.

Different query in same test change query plan.



 Comments   
Comment by Marko Mäkelä [ 2024-01-22 ]

Finally, I found MDEV-20169, where something similar was analyzed some time ago. I think that this may require a similar fix.

Generated at Thu Feb 08 10:36:14 UTC 2024 using Jira 8.20.16#820016-sha1:9d11dbea5f4be3d4cc21f03a88dd11d8c8687422.