Lucene 2.3 has been released[1] with many improvements (not sure how many of them directly apply under Compass though). Many improvements have been made to Compass 2.0M1 too. It would be nice if both could be combined. I tried the latest 2.0M1 snapshot and I hit an exception[2]. [1] http://www.nabble.com/-ANNOUNCE--Lucene-Java-2.3.0-release-available-td15080226.html [2] java.lang.NoSuchMethodError: org.apache.lucene.index.IndexFileDeleter.<init>(Lorg/apache/lucene/store/Directory;Lorg/apache/lucene/index/IndexDeletionPolicy;Lorg/apache/lucene/index/SegmentInfos;Ljava/io/PrintStream;)V at org.apache.lucene.index.TransIndex.<init>(TransIndex.java:167) at org.apache.lucene.index.TransIndex.<init>(TransIndex.java:115) at org.compass.core.lucene.engine.transaction.ReadCommittedTransaction$TransIndexManager.openTransIndexBySubIndex(ReadCommittedTransaction.java:177) at org.compass.core.lucene.engine.transaction.ReadCommittedTransaction.doCreate(ReadCommittedTransaction.java:337) at org.compass.core.lucene.engine.transaction.AbstractTransaction.create(AbstractTransaction.java:109) at org.compass.core.lucene.engine.LuceneSearchEngine.create(LuceneSearchEngine.java:348) at org.compass.core.impl.DefaultCompassSession.create(DefaultCompassSession.java:350) at org.compass.gps.device.jpa.AbstractCompassJpaEntityListener$1.doInCompassWithoutResult(AbstractCompassJpaEntityListener.java:108) at org.compass.core.CompassCallbackWithoutResult.doInCompass(CompassCallbackWithoutResult.java:29) at org.compass.core.CompassTemplate.execute(CompassTemplate.java:132) at org.compass.core.CompassTemplate.execute(CompassTemplate.java:114) at org.compass.gps.device.jpa.AbstractCompassJpaEntityListener.postPersist(AbstractCompassJpaEntityListener.java:106) at org.compass.gps.device.jpa.lifecycle.TopLinkEssentialsJpaEntityLifecycleInjector$TopLinkEssentialsEventListener.postInsert(TopLinkEssentialsJpaEntityLifecycleInjector.java:63)