DBMS Compatibility

Firebird

Auto-table creation is severely limited with Firebird. In Firebird, DDL statements are not auto-committed and are executed at the end of a transaction, after any DML statements. This makes "on the fly" table creation in the middle of a DML transaction not work. Instead, you can use TJDO's SchemaManager to explicitly create tables (but auto-table creation mode must still be enabled). For example:

PersistenceManager pm = ...
SchemaManager sm = SchemaManagerFactory.getSchemaManager(pm);

sm.addClasses(new Class[] { Foo.class, Bar.class });

MySQL

The isEmpty() method and certain forms of contains() are not supported in query filters. They rely on subqueries, which MySQL does not yet support (although this is slated for 4.1).

View objects are not available since MySQL doesn't support views.

Oracle 8.1.x

On Oracle, class names must be chosen such that they do not result in table names that collide with Oracle SQL keywords. This is due to a bug in Oracle's implementation of DatabaseMetaData.getIndexInfo(), which fails for such table names.

This bug is known to exist at least in versions 8.1.6 and 8.1.7 of Oracle's JDBC thin driver. The class naming limitation will be eliminated if and when the bug is fixed by Oracle, without requiring any changes to TJDO.

Oracle 9.x

TJDO does not (yet) attempt to make use of the new 9i TIMESTAMP data types. All date/time types are mapped to Oracle's DATE type, as done with 8i. For various unfortunate reasons (mostly having to do with Oracle's reluctance to conform to the standard JDBC API), even if you were to manually create your tables with TIMESTAMP columns they cannot be used with TJDO. This may be remedied in a future release.

PostgreSQL 7.2.x

SQL Server