Well, I tested only with pure JDBC, maybe Cayenne sets some enviroment
correctly. It'd be great if you tested committed code. You can get compiled
binaries from Hudson:
http://hudson.zones.apache.org/hudson/job/Cayenne-trunk/403/
2009/5/25 stefcl <stefatwor..mail.com>
>
> Here's the code I'm currently using, it's based on the v3 with generics
> version I got from the repo a few days earlier :
>
> DataContext context = DataContext.createDataContext();
>
> SelectQuery query = new SelectQuery(ItemDetail.class);
>
> //query.andQualifier( ExpressionFactory.matchDbExp(
> ItemDetail.PROFILEID_PK_COLUMN, 10 ) );
> //query.andQualifier( ExpressionFactory.likeExp(
> ItemDetail.NAME_PROPERTY, "G%")) ;
> query.addOrdering(ItemDetail.NAME_PROPERTY, Ordering.ASC );
>
> query.setCursorFetchSize( 1000 );
>
> ResultIterator iterator = context.performIteratedQuery(query);
>
> while( iterator.hasNextRow())
> {
> ItemDetail detail = (ItemDetail)context.objectFromDataRow(
> ItemDetail.class, (DataRow)iterator.nextRow(), false);
> System.out.println( detail.getName() + "\t\t\t\t" +
> detail.getKeywords() );
> }
>
> It works...
> If I remove the fetchSize parameter, it fails with following stackTrace :
>
> Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
> at java.lang.Class.getDeclaredFields0(Native Method)
> at java.lang.Class.privateGetDeclaredFields(Class.java:2291)
> at java.lang.Class.getDeclaredField(Class.java:1880)
> at
>
> java.util.concurrent.atomic.AtomicReferenceFieldUpdater$AtomicReferenceFieldUpdaterImpl.<init>(AtomicReferenceFieldUpdater.java:181)
> at
>
> java.util.concurrent.atomic.AtomicReferenceFieldUpdater.newUpdater(AtomicReferenceFieldUpdater.java:65)
> at java.sql.SQLException.<clinit>(SQLException.java:353)
> at
>
> org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1325)
> at
>
> org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:194)
> at
>
> org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:451)
> at
>
> org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:350)
> at
>
> org.postgresql.jdbc2.AbstractJdbc2Statement.executeQuery(AbstractJdbc2Statement.java:254)
> at
>
> org.apache.cayenne.access.jdbc.SelectAction.performAction(SelectAction.java:78)
> at
>
> org.apache.cayenne.access.DataNodeQueryAction.runQuery(DataNodeQueryAction.java:87)
> at
> org.apache.cayenne.access.DataNode.performQueries(DataNode.java:274)
> at
>
> org.apache.cayenne.access.DataDomainLegacyQueryAction.execute(DataDomainLegacyQueryAction.java:79)
> at
> org.apache.cayenne.access.DataDomain$1.transform(DataDomain.java:713)
> at
> org.apache.cayenne.access.DataDomain.runInTransaction(DataDomain.java:833)
> at
> org.apache.cayenne.access.DataDomain.performQueries(DataDomain.java:710)
> at
>
> org.apache.cayenne.access.DataContext.internalPerformIteratedQuery(DataContext.java:1213)
> at
>
> org.apache.cayenne.access.DataContext.performIteratedQuery(DataContext.java:1179)
> at cayenne.CayenneMain.main(CayenneMain.java:43)
>
>
> I'm surprised that you get different results... I use the lastest 8.3.604
> driver from jdbc.
> Otherwise, looking at cayenne logs it seems that a transaction is being
> started :
>
> INFO: --- will run 1 query.
> 25 mai 2009 11:58:35 org.apache.cayenne.access.QueryLogger logConnect
> INFO: Opening connection: jdbc:postgresql://localhost/prediggo_db
> Login: postgres
> Password: *******
> 25 mai 2009 11:58:35 org.apache.cayenne.access.QueryLogger
> logConnectSuccess
> INFO: +++ Connecting: SUCCESS.
> 25 mai 2009 11:58:35 org.apache.cayenne.access.QueryLogger
> logBeginTransaction
> INFO: --- transaction started.
> 25 mai 2009 11:58:36 org.apache.cayenne.access.QueryLogger log
> INFO: Detected and installed adapter:
> org.apache.cayenne.dba.postgres.PostgresAdapter
> 25 mai 2009 11:58:36 org.apache.cayenne.access.QueryLogger logQuery
> INFO: SELECT t0.timest, t0.keywords,
>
>
> If you want, I can test your implementation with my test case but I can't
> afford to spend much time setting up the build environment (jdk 1.5 + maven
> stuff)... If I could get compiled binaries somewhere...
>
>
>
> Andrey Razumovsky wrote:
> >
> > I'm using latest postgres (or mysql) driver. To make a test, I put 1M
> > records in db table, then do "select * from that_table". No matter which
> > fetch size I tried to set, at the moment of PreparedStastement.execute()
> > something about 70-100Mb are allocated (I don't actually remember the
> > quantity right now). So, if heap size is small, I get OutOfMemory.
> > Otherwise, it's all ok and rows can be quickly iterated. Looking at code
> > on
> > postgres site, the only difference is that I didn't bother with
> autocommit
> > mode. I'm not sure Cayenne does, too... Maybe this is the reason why I
> > didn't get positive results.
> >
> > Andrey
> >
>
> --
> View this message in context:
> http://www.nabble.com/Fwd%3A-Big-selects-on-PostGres-%3A-Configuring-Statement.setFetchSize%28%29-of--a-selectquery-tp23703746p23704583.html
> Sent from the Cayenne - Dev mailing list archive at Nabble.com.
>
>
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