Return-Path: Delivered-To: apmail-db-derby-dev-archive@www.apache.org Received: (qmail 2836 invoked from network); 31 Mar 2006 15:33:19 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (209.237.227.199) by minotaur.apache.org with SMTP; 31 Mar 2006 15:33:19 -0000 Received: (qmail 98790 invoked by uid 500); 31 Mar 2006 15:33:19 -0000 Delivered-To: apmail-db-derby-dev-archive@db.apache.org Received: (qmail 98559 invoked by uid 500); 31 Mar 2006 15:33:18 -0000 Mailing-List: contact derby-dev-help@db.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: Delivered-To: mailing list derby-dev@db.apache.org Received: (qmail 98550 invoked by uid 99); 31 Mar 2006 15:33:18 -0000 Received: from asf.osuosl.org (HELO asf.osuosl.org) (140.211.166.49) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 31 Mar 2006 07:33:18 -0800 X-ASF-Spam-Status: No, hits=0.0 required=10.0 tests= X-Spam-Check-By: apache.org Received-SPF: neutral (asf.osuosl.org: local policy) Received: from [204.174.16.215] (HELO mailout5.parasun.com) (204.174.16.215) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 31 Mar 2006 07:33:17 -0800 Received: from cpe-24-143-157-032.cable.alamedanet.net ([24.143.157.32] helo=[127.0.0.1]) by mailout5.parasun.com with esmtp (Exim 4.54) id 1FPLcM-0000Gy-Se for derby-dev@db.apache.org; Fri, 31 Mar 2006 07:32:55 -0800 Message-ID: <442D4BA3.2040404@amberpoint.com> Date: Fri, 31 Mar 2006 07:32:51 -0800 From: Bryan Pendleton User-Agent: Thunderbird 1.5 (Windows/20051201) MIME-Version: 1.0 To: derby-dev@db.apache.org Subject: Re: Does in-place compress really defragment? References: <0IWZ00J4WWUAYO@epost-mail1.sweden.sun.com> In-Reply-To: <0IWZ00J4WWUAYO@epost-mail1.sweden.sun.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Virus-Checked: Checked by ClamAV on apache.org X-Spam-Rating: minotaur.apache.org 1.6.2 0/1000/N �ystein Gr�vlen wrote: > I tried an experiment with on-line compress and it seems like no space > is freed unless I delete records at the end of the heap: It does seem like the documentation allows for this: SYSCS_COMPRESS_TABLE is guaranteed to recover the maximum amount of free space, at the cost of temporarily creating new tables and indexes before the statement in committed. SYSCS_INPLACE_COMPRESS attempts to reclaim space within the same table, but cannot guarantee it will recover all available space. Did you try your same experiment with full compress? thanks, bryan