Alexandr,

> I was somewhat intrigued (and confused) by the InterBase Language
> Reference manual downloadable from Sourceforge, where the CONNECT
> statement is described as attaching "to one or more databases",
> which seemed to imply that multiple databases can be used within the
> same connection - something akin schemas.

I think the possibility to connect to multiple databases described in
documentation belongs to GPRE, an SQL pre-processor for different
languages (but not Java). Also it does not provide you a possibility
to issue a query over multiple databases, it is only a way to open two
[independent] connections. If I'm not wrong, the only possibility to
issue a query over multiple databases is QLI, you can consider it as a
shell with its own language. However it is only available as
standalone tool which handles querying, merge-join, etc. internally.
Firebird server does not provide such possibility yet.

Roman