Subject Re: [ib-support] Internal gds ... problem
Author Daniel Rail

> Hi all,

> I made some updates to my database DDL, and once I disconnected, I
> cannot reconnect again. I get this error from isql:

> Statement failed, SQLCODE = -902

> internal gds software consistency check (decompression overran buffer
> (179))

> Server is Firebird 1.0.2.

> I cannot gbak, or gfix, both throw the same error as above.

> Any suggestions how to save the data in this database?
> It's is not very important (I can reproduce the data with some
> effort), but it would be better if I could get it back.

Usually, this is related to having more data in a field than it
should have. This can happen if you are using a multi-byte character
set. That's what happened to me. Also, this "could" happen if you
try to reduce the size of a field by modifying the system tables

Try using the command-line tool ISQL to query your tables(if you
observed closely when the error occurred, you probably already know
which table contains the defective data, before performing this task)
and to help you find the record that contains the field that is
causing this error. Once you found the record, do note which one it is
and delete that record in particular. Please do note that there might
be other rows that might contain the same error, so check everything
to make sure before proceeding. Once you are sure everything is fine,
then you can try a backup.

Daniel Rail
Senior System Engineer
ACCRA Group Inc. (
ACCRA Med Software Inc. (