Re: Abnormal performance difference between Postgres and MySQL

>>> Farhan Husain <russoue@gmail.com> wrote:
> The machine postgres is running on has 4 GB of RAM.

In addition to the other suggestions, you should be sure that
effective_cache_size is set to a reasonable value, which would
probably be somewhere in the neighborhood of '3GB'.  This doesn't
affect actual RAM allocation, but gives the optimizer a rough idea how
much data is going to be kept in cache, between both the PostgreSQL
shared_memory setting and the OS cache.  It can make better choices
with more accurate information.

-Kevin