> Are cross database joins

No, each query can only access a single database, however a
transaction can span several databases, and two phase commits work so
it really depends on your needs.

> > > Bulk insert
> > > Bulk update
> > > Bulk fetch

In addition to Set's comments, it does certainly support most things
needed to do Bulk inserts / updates but you may have to temporarily
disable the triggers and indices on the appropriate tables if
performance is a problem. FB supports prepared queries and stored
procedures which allows you to prepare the query once so you don't
have to wait for the optimiser each time.

Adam