Return-Path: Delivered-To: apmail-db-derby-user-archive@www.apache.org Received: (qmail 91710 invoked from network); 14 Mar 2007 17:28:24 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.2) by minotaur.apache.org with SMTP; 14 Mar 2007 17:28:24 -0000 Received: (qmail 61902 invoked by uid 500); 14 Mar 2007 17:28:31 -0000 Delivered-To: apmail-db-derby-user-archive@db.apache.org Received: (qmail 61850 invoked by uid 500); 14 Mar 2007 17:28:30 -0000 Mailing-List: contact derby-user-help@db.apache.org; run by ezmlm Precedence: bulk list-help: list-unsubscribe: List-Post: List-Id: Reply-To: "Derby Discussion" Delivered-To: mailing list derby-user@db.apache.org Received: (qmail 61839 invoked by uid 99); 14 Mar 2007 17:28:30 -0000 Received: from herse.apache.org (HELO herse.apache.org) (140.211.11.133) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 14 Mar 2007 10:28:30 -0700 X-ASF-Spam-Status: No, hits=0.0 required=10.0 tests= X-Spam-Check-By: apache.org Received-SPF: neutral (herse.apache.org: local policy) Received: from [32.97.182.146] (HELO e6.ny.us.ibm.com) (32.97.182.146) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 14 Mar 2007 10:28:17 -0700 Received: from d01relay04.pok.ibm.com (d01relay04.pok.ibm.com [9.56.227.236]) by e6.ny.us.ibm.com (8.13.8/8.13.8) with ESMTP id l2EHSfcm005279 for ; Wed, 14 Mar 2007 13:28:41 -0400 Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by d01relay04.pok.ibm.com (8.13.8/8.13.8/NCO v8.3) with ESMTP id l2EHRs16305476 for ; Wed, 14 Mar 2007 13:27:54 -0400 Received: from d01av03.pok.ibm.com (loopback [127.0.0.1]) by d01av03.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id l2EHRsBF002844 for ; Wed, 14 Mar 2007 13:27:54 -0400 Received: from [127.0.0.1] (sig-9-76-213-85.mts.ibm.com [9.76.213.85]) by d01av03.pok.ibm.com (8.12.11.20060308/8.12.11) with ESMTP id l2EHRqo2002730 for ; Wed, 14 Mar 2007 13:27:53 -0400 Message-ID: <45F8308B.1070801@sbcglobal.net> Date: Wed, 14 Mar 2007 10:27:39 -0700 From: Mike Matrigali Reply-To: mikem_app@sbcglobal.net User-Agent: Mozilla Thunderbird 1.0 (Windows/20041206) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Derby Discussion Subject: Re: out of memory when writing blobs References: <45F6DB94.1080000@free.fr> <45F7B4EB.6000100@free.fr> <20070314113038.GK3557@trapper.coreless.net> <45F7F729.9020104@free.fr> <20070314135825.GL3557@trapper.coreless.net> <20070314141156.GM3557@trapper.coreless.net> <20070314143453.GN3557@trapper.coreless.net> <45F81BB8.4040300@sun.com> In-Reply-To: <45F81BB8.4040300@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 �ystein Gr�vlen wrote: > For tables with Blob or Clob columns, the default page size for the will > be 32 kB. > (Ref. http://db.apache.org/derby/docs/dev/tuning/ctunperf816059.html ) Currently Derby will never have 2 different page sizes in the same table or index. As Oystein points out Derby will automatically choose 32k page size if it determines at create table time that is appropriate. Users can override this choice. So blobs tend to make page cache bigger because page size is bigger, nothing really to do with overflow pages. > > -- > �ystein > > Anders Morken wrote: > >> Anders Morken: >> >>> [...] the page size (Seemed to be 32K in this case [...] >> >> >> Aha. Those 32 kilobyte pages were "overflow pages", created to hold >> rows that won't fit on a regular page. The regular pages were 4 >> kilobytes, the default size, but obviously those 6 megabyte blobs had >> to be split across a few overflow pages. =) >> >> That explains why blob workloads suddenly consume a lot more memory than >> regular workloads with few (if any) overflow pages. Maybe this is >> common knowledge, but I just hadn't realized. =) >> >> Sorry for the noise, just wanted to clear up (my own) confusion. =) >> > > >