In previous versions of JBoss, loading of a CMP or CMR field from a read-ahead cache was accompanied with immediate removal of the loaded data from the read-ahead. Sometimes the removal can cause problems and we would like to leave the data in the read-ahead cache to be able to load the instance in the same transaction again from the read-ahead cache instead of the database.
clean-read-ahead-on-load may appear in standardjbosscmp-jdbc.xml or jbosscmp-jdbc.xml inside elements and may contain either true or false. Since 3.2.5RC1, the default value is false and is set in standardjbosscmp-jdbc.xml, i.e. this is a change in the behaviour comparing to previous versions.