Meghansh,

> Secondly, I know that that htere is no GUID data type here in

Firebird. Can I generate a unique number for a user's session so that
a user can be identified by that session id?

Fill free to use generators for any purpose you want - even a session
ID. Your client can for example execute something like:

SELECT GEN_ID( my_generator, 1) FROM RDB$DATABASE;

The returned value is guaranteed to be unique.

The generator most of course already have been created:

CREATE GENERATOR my_generator;

HTH,
Fabrice