Helen,

> >select null as TABLE_CAT, null as TABLE_SCHEM,
>
> This is the "feature not supported". You can't have an untyped column
> in an output set.

When this behavior was changed? Note, following statement works
perfectly with Firebird 1.0.2 (build 908):

select null as bla from rdb$database

Personally I suspect another part: "... WHERE ? = 'T' ...", but this
should be confirmed.

Thanks!
Roman