Re: [PERFORM] [PATCHES] ARC Memory Usage analysis
Josh Berkus <josh@agliodbs.com>
From: Josh Berkus <josh@agliodbs.com>
To: pgsql-hackers@postgresql.org
Cc: Thomas F.O'Connell <tfo@sitening.com>,
Simon Riggs <simon@2ndquadrant.com>, PgSQL - Performance <pgsql-performance@postgresql.org>
Date: 2004-10-27T00:39:59Z
Lists: pgsql-hackers, pgsql-performance
Thomas, > As a result, I was intending to inflate the value of > effective_cache_size to closer to the amount of unused RAM on some of > the machines I admin (once I've verified that they all have a unified > buffer cache). Is that correct? Currently, yes. Right now, e_c_s is used just to inform the planner and make index vs. table scan and join order decisions. The problem which Simon is bringing up is part of a discussion about doing *more* with the information supplied by e_c_s. He points out that it's not really related to the *real* probability of any particular table being cached. At least, if I'm reading him right. -- --Josh Josh Berkus Aglio Database Solutions San Francisco