Received: from localhost (unknown [200.46.204.183]) by developer.postgresql.org (Postfix) with ESMTP id 341E32E0045 for ; Wed, 11 Jun 2008 20:36:53 -0300 (ADT) Received: from developer.postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 36346-01-2 for ; Wed, 11 Jun 2008 20:36:21 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by developer.postgresql.org (Postfix) with ESMTP id 027FC2E00B4 for ; Wed, 11 Jun 2008 20:35:33 -0300 (ADT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.14.2/8.14.2) with ESMTP id m5BNZ9uv024778; Wed, 11 Jun 2008 19:35:09 -0400 (EDT) To: Bruce Momjian cc: Andrew Dunstan , Greg Smith , Andreas Pflug , "Decibel!" , Peter Eisentraut , pgsql-hackers@postgresql.org, Josh Berkus Subject: Re: Overhauling GUCS In-reply-to: <200806112300.m5BN0Dc13952@momjian.us> References: <200806112300.m5BN0Dc13952@momjian.us> Comments: In-reply-to Bruce Momjian message dated "Wed, 11 Jun 2008 19:00:13 -0400" Date: Wed, 11 Jun 2008 19:35:09 -0400 Message-ID: <24777.1213227309@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200806/529 X-Sequence-Number: 119642 Bruce Momjian writes: > The second idea is the idea of having one parameter depend on another. > Not only could we do that for some of our existing parameters, but we > could have pseudo-parameters like concurrent_queries, memory_usage, and > extra_disk_space that could be at the top of postgresql.conf and then > affect the other settings. We have tried to do that in the past, and it didn't work well *at all*. The idea has a fundamental logical flaw, which is that it's not clear which parameter wins if the user changes both. regards, tom lane