Received: from maia.hub.org (unknown [200.46.208.211]) by mail.postgresql.org (Postfix) with ESMTP id 5B06A63388D for ; Sat, 20 Feb 2010 23:25:17 -0400 (AST) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.208.211]) (amavisd-maia, port 10024) with ESMTP id 45419-06 for ; Sun, 21 Feb 2010 03:24:57 +0000 (UTC) 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 mail.postgresql.org (Postfix) with ESMTP id 94E7D6337F4 for ; Sat, 20 Feb 2010 23:25:06 -0400 (AST) 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 o1L3P3be028111; Sat, 20 Feb 2010 22:25:04 -0500 (EST) To: "=?ISO-8859-1?B?dGVycnk=?=" <94487509@qq.com> cc: "=?ISO-8859-1?B?cGdzcWwtcGVyZm9ybWFuY2VAcG9zdGdyZXNxbC5vcmc=?=" Subject: Re: can we optimize STACK_DEPTH_SLOP In-reply-to: References: Comments: In-reply-to "=?ISO-8859-1?B?dGVycnk=?=" <94487509@qq.com> message dated "Sun, 21 Feb 2010 10:53:09 +0800" Date: Sat, 20 Feb 2010 22:25:03 -0500 Message-ID: <28110.1266722703@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-1.535 tagged_above=-10 required=5 tests=AWL=-0.795, BAYES_20=-0.74 X-Spam-Level: X-Archive-Number: 201002/286 X-Sequence-Number: 37707 "=?ISO-8859-1?B?dGVycnk=?=" <94487509@qq.com> writes: > STACK_DEPTH_SLOP stands for Required daylight between max_stack_depth and the kernel limit, in bytes. > Why we need so much memory? MySql need only no more than 100K. Where these memory allocated for? That's not memory, that's just address space. Cutting it will not really buy you anything; it'll just increase your risk of stack-overflow crashes. regards, tom lane