Yup. In my experiences, I found Firebird executes SELECT query very slow on
multiple tables access. And more if it include sort command (ORDER BY). And
more if it processes thousands rows or greater. And even much slower
especially on UPDATE command. Even on a simple database structure!

Though it can be done, it's not as easy as just write SQL statements. To
have fast query execution, there are many things to be tuned up here and
there, such as setting the database page size, adding indexes, adding query
plan, etc. And after I did the tune up things, sometimes the result is not
as fast as I expected.

Compare it with mySQL. I agree with someone who said the power of mySQL is
the simplicity. Though, it doesn't mean that mySQL is better than Firebird
in all things, because in some other things Firebird is much better than
mySQL (triggers, SPs, transaction, etc). But for speed, I have to admit that
mySQL is very very much faster than Firebird.

I hope in the next version of Firebird (v.2.0 perhaps), the query execution
speed can be improved much. I know it's hard to be as fast as mySQL, but at
least the difference is less than 2-3 seconds.

This is a very subjective opinion of mine. Hope someone can correct me if
I'm wrong. :)

Regards,

-Bee-