On Aug 30, 2006, at 5:29 AM, Matthew Sullivan wrote:
The hardware is a Compaq 6400r with 4G of EDO RAM, 4x500MHz Xeons and a Compaq RAID 3200 in RAID 5 configuration running across 3 spindles (34G total space).The OS is FreeBSD 5.4-RELEASE-p14 The PG Version is 8.1.3
What else does this box do?I think you should try these settings, which I use on 4GB dual Opteron boxes running FreeBSD 6.x dedicated to Postgres only. Your effective_cache_size seems overly optimistic for freebsd. cranking up the shared buffers seems to be one of the best bangs for the buck under pg 8.1. I recently doubled them and nearly tripled my performance on a massive write-mostly (insert/update) load. Unless your disk system is *really* slow, random_page_cost should be reduced from the default 4.
As you can see, I change *very* little from the default config.shared_buffers = 70000 # min 16 or max_connections*2, 8KB each
work_mem = 262144 # min 64, size in KB maintenance_work_mem = 524288 # min 1024, size in KB checkpoint_segments = 256 checkpoint_timeout = 900effective_cache_size = 27462 # `sysctl -n vfs.hibufspace` / 8192 (BLKSZ)
random_page_cost = 2if you're feeling adventurous try these to reduce the checkpoint impact on the system:
bgwriter_lru_percent = 2.0 bgwriter_lru_maxpages = 40 bgwriter_all_percent = 0.666 bgwriter_all_maxpages = 40 =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Vivek Khera, Ph.D. MailerMailer, LLC Rockville, MD http://www.MailerMailer.com/ +1-301-869-4449 x806
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