| From: | "Ho Fat Tsang" <namiwf(at)gmail(dot)com> | 
|---|---|
| To: | "Richard Huxton" <dev(at)archonet(dot)com> | 
| Cc: | pgsql-performance(at)postgresql(dot)org | 
| Subject: | Re: PostgreSQL 8.0 occasionally slow down | 
| Date: | 2007-06-28 08:01:30 | 
| Message-ID: | 97e6e20f0706280101y543b871ao4cbf85e57f07f7e9@mail.gmail.com | 
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| Lists: | pgsql-performance | 
Hi Richard,
   I have tuned the checkpoint_timeout to 30 second which is ten times less
than default and the issue is still reproduced. Do you have any recommended
configuration for WAL ?
Thanks
Twinsen
2007/6/28, Richard Huxton <dev(at)archonet(dot)com>:
>
> Ho Fat Tsang wrote:
> >
> >   I am new for postgresql server. And now i work on a projects which
> > requires postgreSQL 8.0 and Java. I don't know why the server
> occasionally
> > slow down a bit for every 3 minutes.
>
> > Do anyone can help me about this ? or any resolution for a sudden
> > performance degrade ( because the application i need to develop is quite
> > time-critical).
>
> It's probably checkpointing. PG will write updates to the transaction
> log (WAL) immediately and update the main data files later. Every so
> often it makes sure the data files are up-to-date and this is called
> checkpointing.
>
> You want checkpointing to happen more often, not less. That way the load
> will be less each time it happens. See the manual for details.
>
> --
>    Richard Huxton
>    Archonet Ltd
>
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