--- In firebird-support@yahoogroups.com, Ray Holme <rholme@...> wrote:

>
> This is an old problem. Many drivers do local cache-ing, others do their
> own SQL parsing (imagine the effort if you are joining two or more
> tables from different databases). Many years ago, my company wrote a
> driver that did this client-server thing (SQLRunner). We let the server
> interprets the SQL (Oracle has it's own variants just as Firebird and
> Interbase do) so you let the server worry about interpreting the syntax.
> The second problem is how to get data as the syntax for getting the data
> is by field when you get down to the final strokes - we cached as many
> rows for a get as possible with the largest TCP-IP buffer we could
> support and sent parts of an even bigger cache by dividing the 32k
> server cache (or less, depending on how many rows could fit into that)
> into 2k TCP blocks. The result beat the Borland equivalent for Interbase
> by huge factors (20 mins VS 24+ hours to get a million+ rows). Then ODBC
> came out (slow but industry accepted) - so the product was only used by
> a few folks - i.e. still born. Of course, you need access to multiple
> DBs (differing vendors perhaps) and the problem of doing a join between
> two or more databases was left to the programmer. There was (maybe still
> is) some code in the Firebird engine that could be expanded to make an
> EXTERNAL table into a foreign DB object - I had hoped to do something
> with that so the DB engine could do the join for you. Once in place, you
> could join data from Informix (still there?), Ingres (dead), Oracle
> (killing Sun) and Interbase/Firebird DBs - all located on different
> machines or (shudder) on the same machine.
>
> I could donate the code to the firebird development group if they want

If i understand correctly you will need to create an external engine in 3.0

https://github.com/asfernandes/firebird/blob/master/examples/udr/UdrCppExample.cpp

If you need more info ask on firebird-devel