| From: | Robert Haas <robertmhaas(at)gmail(dot)com> |
|---|---|
| To: | Tomas Vondra <tv(at)fuzzy(dot)cz> |
| Cc: | pgsql-performance(at)postgresql(dot)org |
| Subject: | Re: Performance degradation of inserts when database size grows |
| Date: | 2011-05-23 19:05:44 |
| Message-ID: | BANLkTikEGR0Mz-bRbk4eXrFtgLt6vC4t_w@mail.gmail.com |
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| Lists: | pgsql-performance |
On Mon, May 23, 2011 at 2:46 PM, Tomas Vondra <tv(at)fuzzy(dot)cz> wrote:
> Really? He already has 64 checkpoint segments, which is about 1GB of
> xlog data. The real problem is that the amount of buffers to write is
> constantly growing. At the beginning there's 62861 buffers (500MB) and
> at the end there's 137657 buffers (1GB).
>
> IMHO increasing the number of checkpoint segments would make this
> disruption even worse.
Maybe - but it would also make the checkpoints less frequent, which
might be a good thing.
> In 9.1 there's a feature that spreads checkpoint writes, but with 8.4
> that's not possible.
What feature are you referring to here? Checkpoint spreading was
added in 8.3, IIRC.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
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