Re: LOG: statistics buffer is full

On Jun 22, 2006, at 2:24 AM, Jérôme BENOIS wrote:
>         We use 7.4.6 version and now we have a bad performance on our

You should upgrade to the latest 7.4 version.

> production server. We detected several strange messages in a log
> file :
>
>     LOG:  statistics buffer is full
>     LOG:  statistics buffer is full
>     LOG:  statistics buffer is full
>
> When i search on mailings list archive, i found a patch to increase
> the
> buffer size in src/include/pgstat.h
>
> -#define PGSTAT_RECVBUFFERSZ ((int) (1024 * sizeof(PgStat_Msg)))
> +#define PGSTAT_RECVBUFFERSZ ((int) (16384 * sizeof(PgStat_Msg)))
>
> And when i look the same file on the subversion trunk, the
> "PGSTAT_RECVBUFFERSZ" constant is defined in a new file :
> src/backend/postmaster/pgstat.c but with a same value.
>
> Can you explain this statistics buffer problem ? And increase this
> buffer size is a good resolution ?

Do you have stats_command_string=on? If so, your best bet is probably
to disable that, because it has a very high overhead (I've seen as
much as over 50%). FWIW, Tom recently made changes in HEAD that
essentially remove the overhead for using stats_command_string.
--
Jim C. Nasby, Sr. Engineering Consultant      jnasby@pervasive.com
Pervasive Software      http://pervasive.com    work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf       cell: 512-569-9461