Re: Problem with database performance, Debian 4gb ram ?

Grant Masan wrote:
> Hi Hi all,
>
> I have now readed many many forums and tried many different solutions
> and I am not getting good performance to database. My server is Debian
> linux, with 4gb ram, there is also java application and I am giving to
> that 512mb (JAVA_OPTS) memory. In database there is now like 4milj rows.
> What should I do better.
> Now .conf is:
>
> max_connections = 80
> shared_buffers = 512MB
> temp_buffers = 8MB
> work_mem = 20MB
> maintenance_work_mem = 384MB
> wal_buffers = 8MB
> checkpoint_segments = 128MB
> effective_cache_size = 2304MB
> cpu_tuple_cost = 0.0030
> cpu_index_tuple_cost = 0.0010
> cpu_operator_cost = 0.0005
> fsync = off
> checkpoint_timeout = 1h
>
> and I am giving kernels like:
>
> sysctl -w kernel.shmmax=1073741824
> sysctl -w kernel.shmall=2097152
>
> btw, what file I should modify to give this kernels as defaults ?
>
> Thank you very much ! Hope you can clear my problem !

You have given almost no information that can be used to help you. In
particular, you seem to be mixing up Java performance and database
performance (JAVA_OPTS has nothing to do with pg performance).

How do you know your performance is low? What is your hardware, what
performance do you get and what do you expect?

If after this you are still convinced the problem is database-related,
you will probably need to run a tool like
http://pqa.projects.postgresql.org/ to search which queries are slow and
then start analyzing each particular query.

In short, there is no magical answer to your question :)