Re: Getting Slow - Mailing list pgsql-performance

From Alvaro Herrera
Subject Re: Getting Slow
Date
Msg-id 20070607185854.GC21004@alvh.no-ip.org
Whole thread Raw
In response to Getting Slow  (Joe Lester <joe_lester@sweetwater.com>)
Responses Re: Getting Slow  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-performance
Joe Lester wrote:

> max_fsm_pages = 150000

This may be a bit too low -- it's just a little more than 1 GB, which
means it might fail to keep track of all your tables (or it may not, if
you don't have many updates).

> autovacuum_naptime = 60
> autovacuum_vacuum_threshold = 150
> autovacuum_vacuum_scale_factor = 0.00000001
> autovacuum_analyze_scale_factor = 0.00000001

The scale factors seems awfully low.  How about 0.01 instead and see if
you avoid vacuuming all your tables with every iteration ... have you
noticed how much work autovacuum is really doing?  It may be too much.

Also if autovacuum is eating all your I/O you may want to look into
throttling it back a bit by setting autovacuum_vacuum_cost_delay to a
non-zero value.

--
Alvaro Herrera                        http://www.advogato.org/person/alvherre
"La tristeza es un muro entre dos jardines" (Khalil Gibran)

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