pg.ddx.io pgsql-bugs@postgresql.org mailing list archive
help / color / mirror / Atom feedDocumentation bug at: current/sql-vacuum.html, Notes
3+ messages / 2 participants
[nested] [flat]
* Documentation bug at: current/sql-vacuum.html, Notes
@ 2023-07-26 17:39 Christophe Pettus <xof@thebuild.com>
0 siblings, 1 reply; 3+ messages in thread
From: Christophe Pettus @ 2023-07-26 17:39 UTC (permalink / raw)
To: pgsql-bugs@lists.postgresql.org
Isn't this backwards?
> If index cleanup is not performed regularly, performance may suffer, because as the table is modified indexes will accumulate dead tuples and the table itself will accumulate dead line pointers that cannot be removed until index cleanup is completed.
Indexes have line pointers, tables have tuples, so it should read:
> If index cleanup is not performed regularly, performance may suffer, because as the table is modified indexes will accumulate dead line pointers and the table itself will accumulate dead tuples that cannot be removed until index cleanup is completed.
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: Documentation bug at: current/sql-vacuum.html, Notes
@ 2023-07-26 17:55 Nathan Bossart <nathandbossart@gmail.com>
parent: Christophe Pettus <xof@thebuild.com>
0 siblings, 1 reply; 3+ messages in thread
From: Nathan Bossart @ 2023-07-26 17:55 UTC (permalink / raw)
To: Christophe Pettus <xof@thebuild.com>; +Cc: pgsql-bugs@lists.postgresql.org
On Wed, Jul 26, 2023 at 10:39:41AM -0700, Christophe Pettus wrote:
> Isn't this backwards?
>
>> If index cleanup is not performed regularly, performance may suffer, because as the table is modified indexes will accumulate dead tuples and the table itself will accumulate dead line pointers that cannot be removed until index cleanup is completed.
>
> Indexes have line pointers, tables have tuples, so it should read:
>
>> If index cleanup is not performed regularly, performance may suffer, because as the table is modified indexes will accumulate dead line pointers and the table itself will accumulate dead tuples that cannot be removed until index cleanup is completed.
I believe the current phrasing is correct. VACUUM will be able to reclaim
the tuple space in the heap, but the line pointers must remain until their
corresponding index tuples are removed.
--
Nathan Bossart
Amazon Web Services: https://aws.amazon.com
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: Documentation bug at: current/sql-vacuum.html, Notes
@ 2023-07-26 18:12 Christophe Pettus <xof@thebuild.com>
parent: Nathan Bossart <nathandbossart@gmail.com>
0 siblings, 0 replies; 3+ messages in thread
From: Christophe Pettus @ 2023-07-26 18:12 UTC (permalink / raw)
To: Nathan Bossart <nathandbossart@gmail.com>; +Cc: pgsql-bugs@lists.postgresql.org
> On Jul 26, 2023, at 10:55, Nathan Bossart <nathandbossart@gmail.com> wrote:
>
>
> I believe the current phrasing is correct. VACUUM will be able to reclaim
> the tuple space in the heap, but the line pointers must remain until their
> corresponding index tuples are removed.
Ah, right, thanks.
^ permalink raw reply [nested|flat] 3+ messages in thread
end of thread, other threads:[~2023-07-26 18:12 UTC | newest]
Thread overview: 3+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2023-07-26 17:39 Documentation bug at: current/sql-vacuum.html, Notes Christophe Pettus <xof@thebuild.com>
2023-07-26 17:55 ` Nathan Bossart <nathandbossart@gmail.com>
2023-07-26 18:12 ` Christophe Pettus <xof@thebuild.com>
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox