diff --git a/doc/TODO.detail/performance b/doc/TODO.detail/performance index 7c219b61f8..73e61b9391 100644 --- a/doc/TODO.detail/performance +++ b/doc/TODO.detail/performance @@ -345,7 +345,7 @@ From owner-pgsql-hackers@hub.org Tue Oct 19 10:31:10 1999 Received: from renoir.op.net (root@renoir.op.net [209.152.193.4]) by candle.pha.pa.us (8.9.0/8.9.0) with ESMTP id KAA29087 for ; Tue, 19 Oct 1999 10:31:08 -0400 (EDT) -Received: from hub.org (hub.org [216.126.84.1]) by renoir.op.net (o1/$Revision: 1.3 $) with ESMTP id KAA27535 for ; Tue, 19 Oct 1999 10:19:47 -0400 (EDT) +Received: from hub.org (hub.org [216.126.84.1]) by renoir.op.net (o1/$Revision: 1.4 $) with ESMTP id KAA27535 for ; Tue, 19 Oct 1999 10:19:47 -0400 (EDT) Received: from localhost (majordom@localhost) by hub.org (8.9.3/8.9.3) with SMTP id KAA30328; Tue, 19 Oct 1999 10:12:10 -0400 (EDT) @@ -454,7 +454,7 @@ From owner-pgsql-hackers@hub.org Tue Oct 19 21:25:30 1999 Received: from renoir.op.net (root@renoir.op.net [209.152.193.4]) by candle.pha.pa.us (8.9.0/8.9.0) with ESMTP id VAA28130 for ; Tue, 19 Oct 1999 21:25:26 -0400 (EDT) -Received: from hub.org (hub.org [216.126.84.1]) by renoir.op.net (o1/$Revision: 1.3 $) with ESMTP id VAA10512 for ; Tue, 19 Oct 1999 21:15:28 -0400 (EDT) +Received: from hub.org (hub.org [216.126.84.1]) by renoir.op.net (o1/$Revision: 1.4 $) with ESMTP id VAA10512 for ; Tue, 19 Oct 1999 21:15:28 -0400 (EDT) Received: from localhost (majordom@localhost) by hub.org (8.9.3/8.9.3) with SMTP id VAA50745; Tue, 19 Oct 1999 21:07:23 -0400 (EDT) @@ -695,3 +695,47 @@ LRU-2 idea and am not pursuing it. regards, tom lane +From pgsql-hackers-owner+M3455@postgresql.org Fri Jan 19 13:18:12 2001 +Received: from mail.postgresql.org (webmail.postgresql.org [216.126.85.28]) + by candle.pha.pa.us (8.9.0/8.9.0) with ESMTP id NAA02092 + for ; Fri, 19 Jan 2001 13:18:12 -0500 (EST) +Received: from mail.postgresql.org (webmail.postgresql.org [216.126.85.28]) + by mail.postgresql.org (8.11.1/8.11.1) with SMTP id f0JIFJ037872; + Fri, 19 Jan 2001 13:15:19 -0500 (EST) + (envelope-from pgsql-hackers-owner+M3455@postgresql.org) +Received: from sectorbase2.sectorbase.com ([208.48.122.131]) + by mail.postgresql.org (8.11.1/8.11.1) with ESMTP id f0JI7V036780 + for ; Fri, 19 Jan 2001 13:07:31 -0500 (EST) + (envelope-from vmikheev@SECTORBASE.COM) +Received: by sectorbase2.sectorbase.com with Internet Mail Service (5.5.2653.19) + id ; Fri, 19 Jan 2001 09:46:14 -0800 +Message-ID: <8F4C99C66D04D4118F580090272A7A234D329F@sectorbase1.sectorbase.com> +From: "Mikheev, Vadim" +To: "'Tom Lane'" , Bruce Momjian +Cc: pgsql-hackers@postgresql.org +Subject: RE: [HACKERS] Possible performance improvement: buffer replacemen + t policy +Date: Fri, 19 Jan 2001 10:07:27 -0800 +MIME-Version: 1.0 +X-Mailer: Internet Mail Service (5.5.2653.19) +Content-Type: text/plain; + charset="iso-8859-1" +Precedence: bulk +Sender: pgsql-hackers-owner@postgresql.org +Status: OR + +> > Tom, did we ever test this? I think we did and found that +> > it was the same or worse, right? +> +> I tried it and didn't see any noticeable improvement on the particular +> test case I was using, so I got discouraged and didn't pursue the idea +> further. I'd like to come back to it someday, though. + +I don't know how much useful could be LRU-2 but with WAL we should try +to reuse undirty free buffers first, not dirty ones, just to postpone +writes as long as we can. (BTW, this is what Oracle does.) +So, we probably should put new free dirty buffer just before first +undirty one in LRU. + +Vadim +