Firebird is an open source DBMS that emerged when Interbase version 6.0 was open source for the community under the IPL license, Interbase Public License. However the new versions of Interbase remained with their closed source code and from then on Firebird and Interbase became separate things, that is, the Firebird was a Fork of Interbase 6.0.
For this reason most things are compatible between them, however I always recommend using the fbclient.dll
, because you might be surprised in some situation that the comics eventually differentiated themselves.
As for the extension, it does not affect the functioning in what depends on the DBMS, the good thing is to use the .fdb
to make it clear that the database you are using is Firebird and not Interbase. What depends on the operating system there is a hassle when working with Windows, since from Windows XP and its recovery system the extension .gdb
is part of a list of extensions that are copied every time the file is changed. Since Firebird modifies the file for each transaction if the database is too large the performance can be highly impaired.
Sources: Clubedelphi and Firebird FAQ