>> There is no performance improvement [with Jaybird] in using
> executeBatch() compared to simple executeUpdate().

> Is this a Firebird engine limitation?
> ...
> I don't know the Firebird APIs. Can a list of parameters be sent to the
> server, or must they be sent one at a time?

Yes, there is no corresponding API call. There is only isc_dsql_exec2 which
allows only one call at a time.

> On other databases, we had large measurable improvements, due to less
> wire traffic and the work being batched on the server.

Try to add this as feature request, and please participate in the API
discussions in Firebird-Architect. There will be no API change for Firebird
2.0, but 3.0 is open (and even more, people are willing to rework the wire
protocol as well as API).

Roman