NotificationsYou must be signed in to change notification settings
Fork6
Star31

Commit3a4837f

committed

Avoid edge case in pg_visibility test with small shared_buffers

Since82a4eda we can bulk extend relations. The bulk relation extensionlogic has a heuristic component. Normally the heurstic does not trigger in theoccasionally-failing test case, as the relation is only extended once. Butwith very small shared_buffers the limits for the number of buffers pinned atonce prevent the extension from happening at once. With the second "bulk"extension, the heuristic kicks in, and the relation ends up one block bigger.That's ok from a correctness perspective, but changes the results of the testquery due to one additional block.We discussed a few more expansive fixes, but for now have decided to avoidthis by making the table a bit smaller.Author: Heikki Linnakangas <hlinnaka@iki.fi>Reported-by:Discussion:https://postgr.es/m/29c74104-210b-ef39-2522-27a6aa7a704f@iki.fiDiscussion:https://postgr.es/m/20230916000011.2ugpkkkp7bpp4cfh@awork3.anarazel.deBackpatch: 16-, where the new relation extension logic was added

1 parent41d3780 commit3a4837fCopy full SHA for 3a4837f

File tree

2 files changed

-8

lines changed

contrib/pg_visibility
- expected
  - pg_visibility.out
- sql
  - pg_visibility.sql

2 files changed

-8

lines changed

`‎contrib/pg_visibility/expected/pg_visibility.out`

Lines changed: 1 addition & 2 deletions

Original file line number	Diff line number	Diff line change
`@@ -217,8 +217,7 @@ select * from pg_visibility_map('copyfreeze');`
`217`	`217`	`-------+-------------+------------`
`218`	`218`	`0 \| t \| t`
`219`	`219`	`1 \| t \| t`
`220`		`- 2 \| t \| t`
`221`		`-(3 rows)`
	`220`	`+(2 rows)`
`222`	`221`
`223`	`222`	`select * from pg_check_frozen('copyfreeze');`
`224`	`223`	`t_ctid`

`‎contrib/pg_visibility/sql/pg_visibility.sql`

Lines changed: 0 additions & 6 deletions

Original file line number	Diff line number	Diff line change
`@@ -108,12 +108,6 @@ copy copyfreeze from stdin freeze;`
`108`	`108`	`4'4'`
`109`	`109`	`5'5'`
`110`	`110`	`6'6'`
`111`		`-7'7'`
`112`		`-8'8'`
`113`		`-9'9'`
`114`		`-10'10'`
`115`		`-11'11'`
`116`		`-12'12'`
`117`	`111`	`\.`
`118`	`112`	`commit;`
`119`	`113`	`select*from pg_visibility_map('copyfreeze');`

0 commit comments

Comments

(0)

Movatterモバイル変換

Navigation Menu

Search code, repositories, users, issues, pull requests...

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

Commit3a4837f

File tree

2 files changed

2 files changed

`‎contrib/pg_visibility/expected/pg_visibility.out`

`‎contrib/pg_visibility/sql/pg_visibility.sql`

0 commit comments