Vlad Horsun wrote:

>> Would the engine understand the @ syntax and ignore anything metadata related
>> coming from that?
>>
>
> Engine will understand @ syntax and will check remote query fields against field
> names specified in query and data types of target variables\parameters.
>
> It is described at (6.a) section (referred as "EXECUTE STATEMENT ... ON" but
> applicable to any remote query)
>
>

How do you propose to handle metadata and system tables? Existing tools
are going to expect that RDB$RELATIONS, RDB$FIELDS, and
RDB$RELATION_FIELDS are appropriately populated? This may be more
difficult than you expect since there can be name collisions between the
remote and local RDB$RELATION_FIELDS.

The last dozen or two times this has come up, the architecture has been
to make a provider (the "mega-database manager") that handles cross
database stuff rather than trying to integrate the mega-database manager
into the existing Firebird database engine. Starting over with a clean
implementation designed to support the specific problem at hand would
probably be easier and better than trying to get a 23 year old database
engine to handle something it was never intended to do.