Received: from localhost (mx1.hub.org [200.46.208.251]) by postgresql.org (Postfix) with ESMTP id 861DB9FB322 for ; Mon, 16 Oct 2006 09:57:33 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.208.251]) (amavisd-new, port 10024) with ESMTP id 98734-05 for ; Mon, 16 Oct 2006 09:57:25 -0300 (ADT) X-Greylist: delayed 00:29:23.434376 by SQLgrey- Received: from svr4.postgresql.org (svr4.postgresql.org [66.98.251.159]) by postgresql.org (Postfix) with ESMTP id 159D39FB28C for ; Mon, 16 Oct 2006 09:57:25 -0300 (ADT) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.3 Received: from skunk.mtbrook.bozemanpass.com (unknown [69.145.82.195]) by svr4.postgresql.org (Postfix) with ESMTP id 225505AF038 for ; Mon, 16 Oct 2006 12:27:59 +0000 (GMT) Received: from [69.145.82.253] (unknown [69.145.82.253]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by skunk.mtbrook.bozemanpass.com (Postfix) with ESMTP id 57B13558346; Mon, 16 Oct 2006 05:27:54 -0700 (PDT) Message-ID: <45337AAC.6060209@boreham.org> Date: Mon, 16 Oct 2006 06:27:24 -0600 From: David Boreham User-Agent: Mozilla Thunderbird 1.0.7 (Windows/20050923) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Harald Armin Massa Cc: Magnus Hagander , pgsql-performance@postgresql.org Subject: Re: measuring shared memory usage on Windows References: <7be3f35d0610160418u51e4d256k15ee2a5e4ba9433@mail.gmail.com> <6BCB9D8A16AC4241919521715F4D8BCEA357F4@algol.sollentuna.se> <7be3f35d0610160518h649c8f20pee9949a90796c346@mail.gmail.com> In-Reply-To: <7be3f35d0610160518h649c8f20pee9949a90796c346@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0.571 tagged_above=0 required=5 tests=AWL, SPF_FAIL X-Spam-Level: X-Archive-Number: 200610/295 X-Sequence-Number: 21424 > really makes me think that that area is just a comfortable way to > access files on disk as memory areas; with the hope of propably better > caching then not-memory-mapped files. No, absolutely not. CreateFileMaping() does much the same thing as mmap() in Unix. > That would explain my disturbing impressions of performance of > PostgreSQL on win32 rising when lowering shared_memory... I don't know what your disturbing impressions are, but no it doesn't explain them.