On Wed, Nov 9, 2011 at 2:25 AM, Venkat Balaji <venkat.balaji@xxxxxxxx> wrote: > Hello Everyone, > I could see the following in the production server (result of the "top" M > command) - > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ > COMMAND > 25265 postgres 15 0 3329m 2.5g 1.9g S 0.0 4.0 > 542:47.83 postgres: writer process > The "writer process" refers to bg_writer ? and we have shared_buffers set to > 1920 MB (around 1.9 GB). So it is using 2.5G of mem of which 1.9G is shared memory (i.e. shared buffers) so the actual amount of RAM it's using is ~600Megs. I see no problem. > In an other similar situation, we have "postgres writer process" using up 7 > - 8 GB memory constantly. I doubt it. Sounds more like you're misreading the output of top. > pg_tune is suggesting to increase the shared_buffers to 8 GB. Reasonable. > If the shared_buffer is not enough, Postgres uses OS cache ? Not really how things work. The OS uses all spare memory as cache. PostgreSQL uses shared_buffers as a cache. The OS is much more efficient about caching in dozens of gigabytes than pgsql is. > We have a 64 GB RAM. > We have decided the following - > 1. We have 20 databases running in one cluster and all are more or less > highly active databases. > 2. We will be splitting across the databases across multiple clusters to > have multiple writer processes working across databases. > Please help us if you have any other solutions around this. You have shown us no actual problem. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
