On Tue, Jul 26, 2011 at 6:02 AM, M. Walter <marc.wal...@sbb.ch> wrote:
> I did the following:
>
> final OpenJPAQuery ojpaQuery =
> OpenJPAPersistence.cast(em.createNamedQuery(
> StammdatenQueryNames.FIND_ALL_BP.name()));
> ojpaQuery.getFetchPlan().removeFetchGroup(FetchGroup.NAME_DEFAULT);
> ojpaQuery.getFetchPlan().addFetchGroup("short");
> final List<Bp> result = ojpaQuery.getResultList();
>
> All fields and all relationships are loaded. Another idea?
>
> I've been following this thread and was inspired to try this myself to
improve a performance problem. I seem to be getting a similar outcome (no
effect). My query code looks like this:
System.out.println("**** 1");
final OpenJPAQuery ojpaQuery = OpenJPAPersistence.cast(query);
ojpaQuery.getFetchPlan().removeFetchGroup(FetchGroup.NAME_DEFAULT); // no
apparent effect
ojpaQuery.getFetchPlan().clearFetchGroups(); // try both ways
ojpaQuery.getFetchPlan().addFetchGroup("ScheduledAssignment.annotated");
salist.addAll(query.getResultList());
System.out.println("**** 2");
I'm getting a boatload of queries between the **** 1 and ****2. I'm
specifically trying to combat an N+1 problem, not sure this approach will
work. Anyway, my annotations on the root entity look like this:
@FetchGroups({
@FetchGroup(name = "ScheduledAssignment.annotated",
attributes = {
@FetchAttribute(name = "request"),
@FetchAttribute(name = "parentScheduledAssignment", recursionDepth = 0),
@FetchAttribute(name = "user"),
@FetchAttribute(name = "standInUser"),
@FetchAttribute(name = "role"),
@FetchAttribute(name = "manualEntry"),
@FetchAttribute(name = "brokenRuleLookup")
})
})
The SQL trace looks like this, I'm showing only the select for only the root
table:
SELECT t0.scheduledassignmentid,
t0.addedby, t0.caseid, t0.scatterautomationid, t0.modifiedby,
t0.rotationassignmentid,
t0.brokencustomruleexplanation, t0.addedon, t0.manualentry, t0.modifiedon,
t0.timedebit
The first line is the PK, the second line FKs, the third basic. There are
more FKs and more basic props. I can't see any pattern to this. After some
back and forth, the select never changes (from t0, I didn't analyze the
others). In fact I reverted to my code prior to using the FetchGroup and
it's no different. I've made all my FKs lazy to no effect. I can't even say
that it appears the default fetch group is still active. What's being
selected doesn't even seem to match that.
I'm using OpenJPA 1.2.2
--
Daryl Stultz
_____________________________________
6 Degrees Software and Consulting, Inc.
http://www.6degrees.com
http://www.opentempo.com
mailto:daryl.stu...@opentempo.com
