Fabiano Bonin wrote:

> I'm making some tests on a database, changing system tables and other
> non recomended things... To more precise, i am deleting all foreign
> keys, primary keys and indices (in the right way) and changing the
> domain of some fields in the system tables (ex: update
> rdb$relation_fields set rdb$field_source = 'PS_DATA' where
> rdb$field_name = 'DATA' and rdb$relation_name = 'FER1'). The domains
> are always equal or larger in space compared to the original field
> type.

Then why don't you use the statement that is meant for this:

ALTER TABLE fer1 ALTER data TYPE ps_data;

> My questions are:
> - Should i expect this kind of error with a valid backup file, that
> was done without problems?
> - What can cause this error, since the restore cycle went up to its
> end without any kind of error?

Direct modification of system tables perhaps? ;)

> Thanks.

You forgot to mention the most important thing: which version of
Firebird are you using?

--
Milan Babuskov
http://swoes.blogspot.com/
http://www.flamerobin.org