Re: postgresql log indicate too many execute S_2:COMMIT

leo xu wrote:
> I test postgresql database performance recently,i set
> log_min_duration_statement=1000;
> i monitor pg_log file,i find too many execue S_2:commit
> 10.0.44.21:30170:2012-04-28 11:38:46.340 CSTLOG: duration: 1050.679
ms
> execute S_2: COMMIT
>
> 10.0.44.21:30208:2012-04-28 11:38:46.340 CSTLOG: duration: 1050.576
ms
> execute S_2: COMMIT
>
> 10.0.44.21:30318:2012-04-28 11:38:46.340 CSTLOG: duration: 1028.171
ms
> execute S_2: COMMIT
>
> ........
>
> please explain what meaning,how to cause it ,how to deal with it?thank
you !

It would be helpful to know *how* you test performance.
Also, the PostgreSQL version, operating system, software and hardware
configuration might be interesting.

If COMMIT takes a long time, my first guess would be that it takes a
long time to write the transaction log (the WAL files in pg_xlog) to
disk.

You can try to verify that with a disk performance measuring tool for
your operating system.

Yours,
Laurenz Albe