It is very cumbersome to use custom dialects which are extending OracleSpatial10gDialect. Consider MyOracleSpatial10gDialect as a sub-class of OracleSpatial10gDialect.

public class MyOracleSpatial10gDialect extends OracleSpatial10gDialect {
    public MyOracleSpatial10gDialect() {
        super();
        registerHibernateType(Types.ARRAY, "array");
    }
}

Due to the nature of buildDialect() in the SpatialDialectFactory, MyOracleSpatial10gDialect will pass the test if (dialect instanceof OracleSpatial10gDialect) which will result in a new object of the parent class OracleSpatial10gDialect. This is bad. This way all custom attributes, like additional type mappings, of MyOracleSpatial10gDialect "get lost".

In my persistence unit I specify this custom dialect which is used correctly :

<property name="hibernate.dialect" value="foo.bar.MyOracleSpatial10gDialect"/>

But during initialisation then, the SpatialDialectFactory destroys my dream.