> i said "my local/server computer." server means anywhere.!

not in my brand of english - sorry.

>
> duplication/replication is real solution ?

to me it is - I use it and rely on it.

>
> i know in MySQL, SELECT .......... FROM db1.table1,db2.table1 etc..
> i think its best solution but mysql not really RDMS.! except 5 version.
>
> it is a firebird problem multiple connection or not?

I don't see it as a problem - you obviously do, so the answer is a little
subjective.
but as I said FB does not provide for cross database SQL
Alan