autovacuum and temporary tables

Started by Csaba Nagyabout 20 years ago6 messagesgeneral
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#1Csaba Nagy
nagy@ecircle-ag.com

Hi all,

I have a postgres 8.0 installation, and I'm running autovacuum against
it. I have noticed that it processes temporary tables too, which is in
itself a bit curious, but the problem is that autovacuum might even
crash if a temporary table is suddenly gone while it tries to vacuum
it... that's what happened once here. I'm not sure what are the
necessary conditions to trigger this, it only happened once.

I searched in the release notes and googled a bit, but could not
(quickly) find what's the status of autovacuum vs. temporary tables in
8.1. I have seen that that was one of Tom's outstanding issues with
autovacuum to be included in the core, but was this resolved ?

Thanks,
Csaba.

#2Matthew T. O'Connor
matthew@zeut.net
In reply to: Csaba Nagy (#1)
Re: autovacuum and temporary tables

Exactly which version of 8.0.x? There was a bug fixed around 8.0.5 or
so "Prevent core dump in contrib version of autovacuum when a table has
been dropped. Per report from daveg (not his patch, though)."

The version of autovacuum in 8.1 is a fairly different beast than the
contrib version, and since it was integrated, I think all of Tom's
concerns were dealt with. I highly recommend the 8.1 version over the
contrib version for many reason.

Matt

Csaba Nagy wrote:

Show quoted text

Hi all,

I have a postgres 8.0 installation, and I'm running autovacuum against
it. I have noticed that it processes temporary tables too, which is in
itself a bit curious, but the problem is that autovacuum might even
crash if a temporary table is suddenly gone while it tries to vacuum
it... that's what happened once here. I'm not sure what are the
necessary conditions to trigger this, it only happened once.

I searched in the release notes and googled a bit, but could not
(quickly) find what's the status of autovacuum vs. temporary tables in
8.1. I have seen that that was one of Tom's outstanding issues with
autovacuum to be included in the core, but was this resolved ?

Thanks,
Csaba.

---------------------------(end of broadcast)---------------------------
TIP 2: Don't 'kill -9' the postmaster

#3Csaba Nagy
nagy@ecircle-ag.com
In reply to: Matthew T. O'Connor (#2)
Re: autovacuum and temporary tables

It's version 8.0.almost3, meaning that I used the 8.0 stable CVS branch
just before 8.0.3 was released. I will upgrade this data base to 8.1.x
(the latest released version at the time of upgrade) soon, so if the 8.1
version has the temporary table thing fixed that would be very nice :-)

I also have an instance running 8.0.almost5, so if that has a fix for
the core dump, that would be also nice, cause that instance will not be
migrated to 8.1 very soon.

BTW, did you actually mean to use the 8.1 autovacuum with 8.0 data base
? I can't imagine how that would work :-)

Thanks,
Csaba.

Show quoted text

On Fri, 2006-01-20 at 16:05, Matthew T. O'Connor wrote:

Exactly which version of 8.0.x? There was a bug fixed around 8.0.5 or
so "Prevent core dump in contrib version of autovacuum when a table has
been dropped. Per report from daveg (not his patch, though)."

The version of autovacuum in 8.1 is a fairly different beast than the
contrib version, and since it was integrated, I think all of Tom's
concerns were dealt with. I highly recommend the 8.1 version over the
contrib version for many reason.

Matt

Csaba Nagy wrote:

Hi all,

I have a postgres 8.0 installation, and I'm running autovacuum against
it. I have noticed that it processes temporary tables too, which is in
itself a bit curious, but the problem is that autovacuum might even
crash if a temporary table is suddenly gone while it tries to vacuum
it... that's what happened once here. I'm not sure what are the
necessary conditions to trigger this, it only happened once.

I searched in the release notes and googled a bit, but could not
(quickly) find what's the status of autovacuum vs. temporary tables in
8.1. I have seen that that was one of Tom's outstanding issues with
autovacuum to be included in the core, but was this resolved ?

Thanks,
Csaba.

---------------------------(end of broadcast)---------------------------
TIP 2: Don't 'kill -9' the postmaster

#4Tom Lane
tgl@sss.pgh.pa.us
In reply to: Csaba Nagy (#1)
Re: autovacuum and temporary tables

Csaba Nagy <nagy@ecircle-ag.com> writes:

I have a postgres 8.0 installation, and I'm running autovacuum against
it. I have noticed that it processes temporary tables too, which is in
itself a bit curious, but the problem is that autovacuum might even
crash if a temporary table is suddenly gone while it tries to vacuum
it... that's what happened once here.

8.0.what? I'm wondering if you are missing this 8.0.5 fix:

2005-10-20 12:14 tgl

* contrib/pg_autovacuum/pg_autovacuum.c (REL8_0_STABLE): Prevent
core dump in contrib version of autovacuum when a table has been
dropped. Per report from daveg (not his patch, though).

regards, tom lane

#5Matthew T. O'Connor
matthew@zeut.net
In reply to: Csaba Nagy (#3)
Re: autovacuum and temporary tables

Csaba Nagy wrote:

It's version 8.0.almost3, meaning that I used the 8.0 stable CVS branch
just before 8.0.3 was released. I will upgrade this data base to 8.1.x
(the latest released version at the time of upgrade) soon, so if the 8.1
version has the temporary table thing fixed that would be very nice :-)

I also have an instance running 8.0.almost5, so if that has a fix for
the core dump, that would be also nice, cause that instance will not be
migrated to 8.1 very soon.

BTW, did you actually mean to use the 8.1 autovacuum with 8.0 data base
? I can't imagine how that would work :-)

No I didn't mean to use the 8.1 autovac with 8.0, that can't work.
Please upgrade your 8.0.x to at least 8.0.5 and see if that fixes the
problem.

#6Csaba Nagy
nagy@ecircle-ag.com
In reply to: Matthew T. O'Connor (#5)
Re: autovacuum and temporary tables

OK, I have an 8.0.almost 5 installation which did not have any such
problems yet. The 8.0.~3 instance will soon be migrated to 8.1.latest,
so I will skip the 8.0.5 step, even if it only means install/restart/no
dump - after all I had a single crash in a few months of operation.

I take it granted that the crash situation on table drop is fixed. I
wonder if temporary tables are still added to the autovacuum list in 8.1
or not ?

Thanks,
Csaba.

Show quoted text

On Fri, 2006-01-20 at 17:07, Matthew T. O'Connor wrote:

No I didn't mean to use the 8.1 autovac with 8.0, that can't work.
Please upgrade your 8.0.x to at least 8.0.5 and see if that fixes the
problem.