From dev-return-21250-apmail-openjpa-dev-archive=openjpa.apache.org@openjpa.apache.org Fri Nov 9 11:56:14 2012 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 9B534DDB9 for ; Fri, 9 Nov 2012 11:56:14 +0000 (UTC) Received: (qmail 17189 invoked by uid 500); 9 Nov 2012 11:56:13 -0000 Delivered-To: apmail-openjpa-dev-archive@openjpa.apache.org Received: (qmail 17120 invoked by uid 500); 9 Nov 2012 11:56:13 -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 17096 invoked by uid 99); 9 Nov 2012 11:56:12 -0000 Received: from arcas.apache.org (HELO arcas.apache.org) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 09 Nov 2012 11:56:12 +0000 Date: Fri, 9 Nov 2012 11:56:12 +0000 (UTC) From: "Vermeulen (JIRA)" To: dev@openjpa.apache.org Message-ID: <1448973569.91471.1352462172738.JavaMail.jiratomcat@arcas> In-Reply-To: <24005549.213991294416067135.JavaMail.jira@thor> Subject: [jira] [Comment Edited] (OPENJPA-1920) N+1 select with entities that contain Maps (even with FetchType.EAGER) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 [ https://issues.apache.org/jira/browse/OPENJPA-1920?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13493954#comment-13493954 ] Vermeulen edited comment on OPENJPA-1920 at 11/9/12 11:54 AM: -------------------------------------------------------------- I used the Eclipse debugger which I also used for the related OPENJPA-2296. When JDBCStoreManager.createEagerSelects considers the TestEntity.strings field for parallel select, the expression fms[i].supportsSelect(sel, Select.EAGER_PARALLEL, sm, this, fetch) returns 0 so it is ignored for efficient eager fetching. Does this mean that this kind of mapping does not support parallel fetch? Why not? Is this easy to add? Why doesn't it do join fetch instead? (EDIT: from the debugger I can see that this fetch mode is also considered inside JDBCStoreManager.createEagerSelects but somehow also rejected) was (Author: slowstrider): I used the Eclipse debugger which I also used for the related OPENJPA-2296. When JDBCStoreManager.createEagerSelects considers the TestEntity.strings field for parallel select, the expression fms[i].supportsSelect(sel, Select.EAGER_PARALLEL, sm, this, fetch) returns 0 so it is ignored for efficient eager fetching. Does this mean that this kind of mapping does not support parallel fetch? Why not? Is this easy to add? Why doesn't it do join fetch instead? > N+1 select with entities that contain Maps (even with FetchType.EAGER) > ---------------------------------------------------------------------- > > Key: OPENJPA-1920 > URL: https://issues.apache.org/jira/browse/OPENJPA-1920 > Project: OpenJPA > Issue Type: Improvement > Components: kernel > Affects Versions: 2.0.0 > Reporter: Vermeulen > > When I have an entity that contains a Map, e.g.: > @Entity > public class TestEntity { > @ElementCollection(fetch = FetchType.EAGER) > Map strings = new HashMap(); > } > And I select all existing entities > String query = "SELECT z FROM " + TestEntity.class.getSimpleName() > + " z"; > List result = em.createQuery(query, TestEntity.class) > .getResultList(); > n + 1 selects are performed which can be seen by using > 917 testPU TRACE [main] openjpa.Query - Executing query: SELECT z FROM TestEntity z > 918 testPU TRACE [main] openjpa.jdbc.SQL - executing prepstmnt 17507279 SELECT t0.id, t0.name FROM TestEntity t0 > 918 testPU TRACE [main] openjpa.jdbc.SQL - [0 ms] spent > 919 testPU TRACE [main] openjpa.jdbc.SQLDiag - load field: 'strings' for oid=entities.TestEntity-1 class entities.TestEntity > 919 testPU TRACE [main] openjpa.jdbc.SQL - executing prepstmnt 7493991 SELECT t0.KEY0, t0.value FROM TestEntity_strings t0 WHERE t0.TESTENTITY_ID = ? [params=(long) 1] > 919 testPU TRACE [main] openjpa.jdbc.SQL - [0 ms] spent > 920 testPU TRACE [main] openjpa.jdbc.SQLDiag - load field: 'strings' for oid=entities.TestEntity-51 class entities.TestEntity > 920 testPU TRACE [main] openjpa.jdbc.SQL - executing prepstmnt 7200207 SELECT t0.KEY0, t0.value FROM TestEntity_strings t0 WHERE t0.TESTENTITY_ID = ? [params=(long) 51] > etc..... > It doesn't matter whether or not I use or . > This is extremely inefficient when I wish to load a list of products that have their name set in multiple languages by using a Map from language to String. > As a workaround I can turn the Map into a List and search the List myself for the right entry. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira