Re: Optimize the database performance

On 10/17/2011 04:48 AM, Micka wrote:
> Hi,
>
> I've a postgres 9.1 database used for map generating ( tiles ).
> The system has 24Go RAM and 5 processors.
> I'm using geoserver to generate the tiles.
>
> My data used 8486 MB => psql -d gis -c "SELECT pg_size_pretty(pg_database_size('gis'))"
>
> I've carefully indexes the table by the "the_geom" column.
>
> Here is my database config :
>
> --> change :
> --> listen_addresses = '*'
> --> max_connections = 50
> --> tcp_keepalives_idle = 60 # TCP_KEEPIDLE, in seconds;
> --> shared_buffers = 1024MB # 10% of available RAM
> --> work_mem = 256MB # min 64kB
> --> maintenance_work_mem = 256MB # min 1MB
> --> effective_cache_size = 5120MB
> --> autovacuum = off
>
> sudo nano /etc/sysctl.conf
> --> kernel.shmmax=5368709120
> --> kernel.shmall=5368709120
>
> I wanted to have your opinion about this config ? What can I do to optimize the performance ?
>
> Thank you,
>

Yeah... We're gonna need some more details. Whats slow? Are you CPU bound or IO bound? How many concurrent db connections? What does vmstat look like? And 10% of 24 gig is 2.4 gig, not 1 gig.

Or is this box doing something else. I noticeeffective_cache_size is only 5 gig, so you must be doing other things on this box.

> --> autovacuum = off

Are you vacuuming by hand!? If not this is a "really bad idea" (tm)(c)(r)

-Andy