Re: pg_autovacuum crashes when query fails for temp tables - Mailing list pgsql-hackers

From Matthew T. O'Connor
Subject Re: pg_autovacuum crashes when query fails for temp tables
Date
Msg-id 51628.192.154.91.225.1082476085.squirrel@192.154.91.225
Whole thread Raw
In response to pg_autovacuum crashes when query fails for temp tables  (Bruce Momjian <pgman@candle.pha.pa.us>)
List pgsql-hackers
Yeah, I will, I just don't know when.  I have been trying to get to this
and lots of other pg_autovacuum tasks, but my schedule has been quite
crazy as of late.  Anyway, this should probably be a pretty simple patch,
so I can probably find some time to look at it soon.

Any idea on the 7.4.3 release timeline?

>
> I looked into this and I see a number of cases where pg_autovacuum calls
> send_query(), but doesn't test for a NULL return from the function.
>
> Matthew, would you look into this and submit a patch?  Thanks.
>
> ---------------------------------------------------------------------------
>
> Jeff Boes wrote:
>> Recently I installed and started pg_autovacuum against my new Pg 7.4.1
>> installation. We use a fairly large number of temporary tables within an
>> application (that is, several copies of this application may be running,
>> and each creates and drops several temp tables as they cycle through
>> their workload). Here's what I think happened, based on the log
>> (pg_autovacuum's and the postmaster's):
>>
>> pg_autovacuum.log:
>> [2004-02-15 08:10:01 AM] Performing: ANALYZE "pg_temp_13"."tmp_targs"
>> [2004-02-15 08:10:01 AM] Can not refresh statistics information from the
>> database nexcerpt.
>> [2004-02-15 08:10:01 AM] The error is [ERROR:  relation
>> "pg_temp_13.tmp_targs" does not exist
>>
>> postmaster.log:
>> 2004-02-15 08:10:01 [31563] ERROR:  relation "pg_temp_13.tmp_targs" does
>> not exist
>> 2004-02-15 08:10:01 [31563] LOG:  unexpected EOF on client connection
>>
>>
>> It appears that pg_autovacuum collected the name of a temp table, and
>> later tried to analyze it. The table was gone by then, and this caused
>> the daemon to exit. As this happened on a Sunday morning, my weekend
>> experiment to see how pg_autovacuum would maintain our test database was
>> rather spoiled ... 8-(
>>
>> --
>> Jeff Boes                                      vox 269.226.9550 ext 24
>> Database Engineer                                     fax 269.349.9076
>> Nexcerpt, Inc.                                 http://www.nexcerpt.com
>>            ...Nexcerpt... Extend your Expertise
>>
>>
>> ---------------------------(end of broadcast)---------------------------
>> TIP 8: explain analyze is your friend
>>
>
> --
>   Bruce Momjian                        |  http://candle.pha.pa.us
>   pgman@candle.pha.pa.us               |  (610) 359-1001
>   +  If your life is a hard drive,     |  13 Roberts Road
>   +  Christ can be your backup.        |  Newtown Square, Pennsylvania
> 19073
>
>



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