Cédric Villemain wrote:
> AFAIK effective_cache_size is estimation of OS Page Cache + Estimated
> Cache in shared_buffers.
Yes, the total value you set is used as is, and should include both
pieces of memory. The planner doesn't add the shared_buffers value to
the total first for you, as some people might guess it would.
The only thing effective_cache_size is used for is estimating how
expensive an index is likely to be to use, to make decisions like when
to do an index-based scan instead of just scanning the table itself.
Greg Smith 2ndQuadrant Baltimore, MD
PostgreSQL Training, Services and Support
In response to
pgsql-performance by date
|Next:||From: Greg Stark||Date: 2010-01-30 02:30:19|
|Subject: Re: Constraint propagating for equal fields|
|Previous:||From: Greg Stark||Date: 2010-01-29 18:56:23|
|Subject: Re: Faster CREATE DATABASE by delaying fsync (was 8.4.1 ubuntu karmic slow createdb)|