| From: | Thomas Spreng <spreng(at)socket(dot)ch> |
|---|---|
| To: | PFC <lists(at)peufeu(dot)com> |
| Cc: | pgsql-performance(at)postgresql(dot)org |
| Subject: | Re: Oddly slow queries |
| Date: | 2008-04-16 04:07:04 |
| Message-ID: | AE4F81FF-C8BE-44BC-A79D-48EC5BF20162@socket.ch |
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| Thread: | |
| Lists: | pgsql-performance |
On 16.04.2008, at 01:24, PFC wrote:
>
>> The queries in question (select's) occasionally take up to 5 mins
>> even if they take ~2-3 sec under "normal" conditions, there are no
>> sequencial scans done in those queries. There are not many users
>> connected (around 3, maybe) to this database usually since it's
>> still in a testing phase. I tried to hunt down the problem by
>> playing around with resource usage cfg options but it didn't really
>> made a difference.
>
> Could that be caused by a CHECKPOINT ?
actually there are a few log (around 12 per day) entries concerning
checkpoints:
LOG: checkpoints are occurring too frequently (10 seconds apart)
HINT: Consider increasing the configuration parameter
"checkpoint_segments".
But wouldn't that only affect write performance? The main problems I'm
concerned about affect SELECT queries.
Regards,
Tom
PS: WAL settings are all set to defaults.
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