This has probably been mentioned by others but I'll request it for JDO2.2 since it has certainly been requested enough amongst users groups.
We should take the javax.jdo.Transaction interface and add the following public static final int TRANSACTION_NONE = 0; public static final int TRANSACTION_READ_UNCOMMITTED = 1; public static final int TRANSACTION_READ_COMMITTED = 2; public static final int TRANSACTION_REPEATABLE_READ = 4; public static final int TRANSACTION_SERIALIZABLE = 8; public void setIsolationLevel(int isolation); public int getIsolationLevel(); Definitions of the 5 levels would be broadly as per the java.sql.Connection class. Support for particular levels would always depend on whether the underlying datastore supports that level - not all RDBMS or ODBMS support all. Maybe define setIsolationLevel() to throw a JDOException if the underlying datastore doesn't support that level. Comments ? -- Andy (Java Persistent Objects - http://www.jpox.org)