> I've heard that the FB client library does not support multiple
> threads within the same DB connection. Why is this, and could it be
> changed?

Quite easy. Client library opens one socket per connection. Each
operation happens synchronously: client sends the request and waits
for response. If you try to send information from multiple threads
while receiving responses for previous operations you will simply get
chaos in the socket. To fix this would mean much more troubles
compared to keeping a thread-per-connection-at-a-time principle.

Would I would like to see, is tha possibility to use a transaction
handle outside the connection context. E.g. I start transaction in one
connection, the suspend it, then resume it in another transaction (in
other words support for XA transactions over multiple connections).

Roman