It sure turned out that default settings are not a good fit.
do you know pgtune? it's a good tool for starters, if you want a fast postgres and don't really want to learn what's behind the scenes.
Yeah.. I came across pgtune but noticed that latest version dated 2009-10-29 http://pgfoundry.org/frs/?group_id=1000416 which is kind of outdated. Tar file has settings for pg 8.3. Is still relevant?
random_page_cost=1 might be not what you really want. it would mean that random reads are as fast as as sequential reads, which probably is true only for SSD
What randon_page_cost would be more appropriate for EC2 EBS Provisioned volume that can handle 2,000 IOPS?