Re: what does pg_activity mean when the database is stuck?

I didn't see any from the log. It was just a whole bunch of pretty
standard looking SELECT queries. There were no INSERT/COMMIT statements
which were still active before the SELECT's, just a few which are waiting
after a lot of SELECT statements.

Also, if the process just shows COMMIT, is there any way to see what it's
trying to commit?

On Wed, Jun 11, 2014 at 9:29 AM, Jeff Janes <jeff(dot)janes(at)gmail(dot)com> wrote:

> On Wed, Jun 11, 2014 at 8:59 AM, Si Chen <sichen(at)opensourcestrategies(dot)com>
> wrote:
>
>> I have a problem where postgresql 9.3 got stuck, and the number of
>> postgresql processes increased from about 15 to 225 in 10 minutes.
>>
>> I ran the query:
>> select pid, query_start, waiting, state, query from pg_stat_activity
>> order by query_start;
>>
>> But it showed mostly select statements -- all of them the same one, with
>> a couple of joins. They are not in a waiting state but have been running
>> for over 2 hours.
>>
>> I also checked for locks with the query on
>> http://wiki.postgresql.org/wiki/Lock_Monitoring
>>
>> But it returned no locked tables.
>>
>> So what does this mean? Is the select query getting stuck?
>>
>
> Do you have a huge chunk of newly insert, not yet committed, rows? This
> sounds like the issue where all of the processes fight with each other over
> the right to check uncommitted rows in order to verify that they are
> actually uncommitted.
>
> Cheers,
>
> Jeff
>

--
Si Chen
Open Source Strategies, Inc.
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