[ https://issues.apache.org/jira/browse/OPENJPA-2179?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13264285#comment-13264285 ] Mark Struberg commented on OPENJPA-2179: ---------------------------------------- Btw, I preserved an old output of this phenomenon in a unit test of our app: 2012-04-26 17:13:36,657 [main] DEBUG jdbc.SQL executing prepstmnt 1053577980 SELECT DISTINCT t1.id, t1.optlock, t1.blocked, t1.businessKey, t1.cancelled, t1.comStuOk, t1.courseNr, t1.createdAt, t1.createdBy, t1.deanAcademicAffairsOk, t1.deleted, t1.denied, t1.depStudOk, t1.ects, t1.elearningUrl, t1.firstAnnouncement, t1.formalError, t1.headOk, t1.held, t1.hours, t1.language, t1.lecturerOk, t1.LINKEDCOURSE_ID, t1.modifiedAt, t1.modifiedBy, t1.orgUntCode, t1.semesterCode, t1.titleDe, t1.titleEn, t1.tuwelUrl, t1.typeKey, t1.url, t1.veniaOk, t1.visibilityDateElearningUrl, t1.visibilityDateTuwelUrl FROM Lecturer t0, Course t1 WHERE t0.COURSE_ID = t1.id 2012-04-26 17:13:36,664 [main] DEBUG jdbc.SQL [7 ms] spent 2012-04-26 17:13:36,665 [main] DEBUG jdbc.SQLDiag load: class myapp.core.be.i18n.entities.LocalizedLongString oid: 10060 2012-04-26 17:13:36,665 [main] DEBUG jdbc.SQL executing prepstmnt 196270141 SELECT t0.examModalitiesDe, t0.examModalitiesEn FROM Course t0 WHERE t0.id = ? [params=?] 2012-04-26 17:13:36,669 [main] DEBUG jdbc.SQL [4 ms] spent 2012-04-26 17:13:36,673 [main] DEBUG jdbc.SQLDiag load: class myapp.core.be.i18n.entities.LocalizedLongString oid: 10060 2012-04-26 17:13:36,673 [main] DEBUG jdbc.SQL executing prepstmnt 802857302 SELECT t0.lectureNotesInfoDe, t0.lectureNotesInfoEn FROM Course t0 WHERE t0.id = ? [params=?] 2012-04-26 17:13:36,677 [main] DEBUG jdbc.SQL [4 ms] spent 2012-04-26 17:13:36,682 [main] DEBUG jdbc.SQLDiag load: class myapp.core.be.i18n.entities.LocalizedLongString oid: 10060 2012-04-26 17:13:36,682 [main] DEBUG jdbc.SQL executing prepstmnt 1253026437 SELECT t0.objectiveDe, t0.objectiveEn FROM Course t0 WHERE t0.id = ? [params=?] 2012-04-26 17:13:36,686 [main] DEBUG jdbc.SQL [4 ms] spent 2012-04-26 17:13:36,698 [main] DEBUG jdbc.SQLDiag load: class myapp.core.be.i18n.entities.LocalizedLongString oid: 10060 2012-04-26 17:13:36,698 [main] DEBUG jdbc.SQL executing prepstmnt 199943961 SELECT t0.recommendationDe, t0.recommendationEn FROM Course t0 WHERE t0.id = ? [params=?] 2012-04-26 17:13:36,702 [main] DEBUG jdbc.SQL [4 ms] spent 2012-04-26 17:13:36,728 [main] DEBUG jdbc.SQLDiag load: class myapp.core.be.i18n.entities.LocalizedLongString oid: 10060 2012-04-26 17:13:36,728 [main] DEBUG jdbc.SQL executing prepstmnt 25287543 SELECT t0.remarkDe, t0.remarkEn FROM Course t0 WHERE t0.id = ? [params=?] 2012-04-26 17:13:36,732 [main] DEBUG jdbc.SQL [4 ms] spent 2012-04-26 17:13:36,738 [main] DEBUG jdbc.SQLDiag load: class myapp.core.be.i18n.entities.LocalizedLongString oid: 10060 2012-04-26 17:13:36,738 [main] DEBUG jdbc.SQL executing prepstmnt 1802848163 SELECT t0.contentDe, t0.contentEn FROM Course t0 WHERE t0.id = ? [params=?] 2012-04-26 17:13:36,742 [main] DEBUG jdbc.SQL [4 ms] spent 2012-04-26 17:13:36,750 [main] DEBUG jdbc.SQLDiag load: class myapp.course.be.entities.Course oid: 10060 all the LocalizedLongString are @Embedded fields directly in the Course entity. This effect doesn't happen with the MySqlDictionary. > 'distinct' and 'join' combinations lead lots of unneccessary sub-queries for @Embedded and @Lob fields > ------------------------------------------------------------------------------------------------------ > > Key: OPENJPA-2179 > URL: https://issues.apache.org/jira/browse/OPENJPA-2179 > Project: OpenJPA > Issue Type: Bug > Components: kernel > Affects Versions: 2.2.0 > Reporter: Mark Struberg > Assignee: Mark Struberg > Fix For: 2.3.0 > > > I have an Entity (Course) with a simple @Embedded field and a @Lob. I do not use any LAZY attribution on them! > If I do a normal em.find, the entity will be loaded as a whole (all the fields, including the embedded and the lob will be fetched immediately). > Sidenote: the Lecturer referred in the select is defined as > @OneToMany(mappedBy = "course", > cascade = {CascadeType.PERSIST, CascadeType.REMOVE, CascadeType.MERGE}, > orphanRemoval = true, fetch = FetchType.EAGER) > @OrderColumn(name = "POSITION") > private List lecturers; > The following selects DO work > * "select c from Course c join c.lecturers l " > * "select distinct c from Course c" > The following selects create tons of subqueries! 1 separate sub-query for each @Embedded field, and also for each @Lob > * "select distinct c from Course c join c.lecturers l " > * "select distinct c from Lecturer l join l.course c" > * "select c from Lecturer l join l.course c" > This happens ONLY if I run this stuff against Oracle. In MySQL it seems to work properly. > I'll try to create a unit test for it. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira