extension element for @Index, @ForeignKey, @Unique, @PrimaryKey annotations are needed.

JDO XSD for XML MetaData supports extension tag. But @Index does not have such elements. Ie I cannot specify @Index(members =

, extension=......). Hope this will be included in new releases. The extension is used by ORM Frameworks in order to specify Index access method such HASH, GIST etc ... (these are postgresql specific)