From: Caio Casimiro [mailto:casimiro.lis...@gmail.com] Sent: Monday, November 04, 2013 4:33 PM To: Igor Neyman Cc: Jeff Janes; pgsql-performance@postgresql.org Subject: Re: [PERFORM] Slow index scan on B-Tree index over timestamp field
These are the parameters I have set in postgresql.conf: work_mem = 128MB shared_buffers = 1GB maintenance_work_mem = 1536MB fsync = off synchronous_commit = off effective_cache_size = 2GB The hardware is a modest one: CPU: Intel(R) Atom(TM) CPU 230 @ 1.60GHz RAM: 2GB HD: 1TV 7200 RPM (WDC WD10EZEX-00RKKA0) This machine runs a slackware 14.0 dedicated to the Postgresql. Thank you, Caio With just 2GB RAM, this: shared_buffers = 1GB and this: effective_cache_size = 2GB is too high. You should lower those: shared_buffers = 256MB effective_cache_size = 1GB and see how your execution plan changes. Oh, and this: maintenance_work_mem = 1536MB is also too high. Turning off fsync and synchronous_commit is not very good idea. Regards, Igor Neyman
