Return-Path: X-Original-To: apmail-openjpa-dev-archive@www.apache.org Delivered-To: apmail-openjpa-dev-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id D8F3E965B for ; Mon, 18 Mar 2013 13:56:56 +0000 (UTC) Received: (qmail 47373 invoked by uid 500); 18 Mar 2013 13:56:56 -0000 Delivered-To: apmail-openjpa-dev-archive@openjpa.apache.org Received: (qmail 47173 invoked by uid 500); 18 Mar 2013 13:56:55 -0000 Mailing-List: contact dev-help@openjpa.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: dev@openjpa.apache.org Delivered-To: mailing list dev@openjpa.apache.org Received: (qmail 47151 invoked by uid 99); 18 Mar 2013 13:56:55 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 18 Mar 2013 13:56:55 +0000 X-ASF-Spam-Status: No, hits=-0.1 required=5.0 tests=HTML_MESSAGE,RCVD_IN_DNSWL_MED,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: domain of krishnaprasads@in.ibm.com designates 122.248.162.6 as permitted sender) Received: from [122.248.162.6] (HELO e28smtp06.in.ibm.com) (122.248.162.6) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 18 Mar 2013 13:56:46 +0000 Received: from /spool/local by e28smtp06.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 18 Mar 2013 19:22:29 +0530 Received: from d28dlp01.in.ibm.com (9.184.220.126) by e28smtp06.in.ibm.com (192.168.1.136) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Mon, 18 Mar 2013 19:22:27 +0530 Received: from d28relay02.in.ibm.com (d28relay02.in.ibm.com [9.184.220.59]) by d28dlp01.in.ibm.com (Postfix) with ESMTP id 91000E005A; Mon, 18 Mar 2013 19:27:47 +0530 (IST) Received: from d28av01.in.ibm.com (d28av01.in.ibm.com [9.184.220.63]) by d28relay02.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r2IDuIHO50200790; Mon, 18 Mar 2013 19:26:19 +0530 Received: from d28av01.in.ibm.com (loopback [127.0.0.1]) by d28av01.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r2IDuK6U023232; Mon, 18 Mar 2013 13:56:20 GMT Received: from d23ml183.in.ibm.com (innco16.in.ibm.com [9.182.207.155]) by d28av01.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id r2IDuEBj022732; Mon, 18 Mar 2013 13:56:20 GMT To: users@openjpa.apache.org, dev@openjpa.apache.org MIME-Version: 1.0 Subject: Persistence units X-KeepSent: 758D1B2B:1690B81C-65257B32:004B3948; type=4; name=$KeepSent X-Mailer: Lotus Notes Release 8.5.3 September 15, 2011 From: Krishnaprasad Subbarao Message-ID: Date: Mon, 18 Mar 2013 19:25:05 +0530 X-MIMETrack: Serialize by Router on d23ml183/23/M/IBM(Release 8.5.3FP2HF29 | July 24, 2012) at 18/03/2013 19:25:07, Serialize complete at 18/03/2013 19:25:07 Content-Type: multipart/alternative; boundary="=_alternative 004C76B565257B32_=" X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13031813-9574-0000-0000-000007168E98 X-Virus-Checked: Checked by ClamAV on apache.org --=_alternative 004C76B565257B32_= Content-Type: text/plain; charset="US-ASCII" Hello, I am working on a large application which has around 50 entities and many relational tables. We wish to use OpenJPA 2.1 as a Persistence provider. I would like to know what criteria's should be considered while deciding the number of persistence units to be defined in an application. Following are my questions about persistence units 1) What are points to be considered to decide how many persistence units should be created in an application? 2) Is it recommended to have one persistence unit per logical module (Business module) in an application? While exploring I found that multiple persistence units are created mostly if different entities are packaged in different WAR/JAR/EAR files. Is this the only criteria to have multiple units? Regards, Krishnaprasad (Kp) --=_alternative 004C76B565257B32_=--