Commented by: Sean Leyne (seanleyne)

This is expected, as designed functionality. A backup is never backward compatible, only forward.

There is a technique to allow for a backup of a 2.0 database to be made using the 1.5 GBak executable. Please post a message to the Support mail list for details on this solution.

Commented by: ohenri (ohenri)

In general and for most DBMS like UDB, Oracle etc, a backup is always backward compatible.

There are good reasons to do so, because a fallback to an older DB version is often the last chance to keep a system avalilable in a short time (when the new version is failing).

And the term "Transportable Format" say's it is transportable between platforms, but it does not specify 'of the same versions'.

Anyway, thanks for the hint, but I already pumped back the DB's manually.

Commented by: Claudio Valderrama C. (robocop)

You can do that with FB2.1's gbak.
You use gbak 2.1 to connect to the old server and it will try to push only the features that the old server understands. Theoretically, it supports even IB4.
Of course, triggers and procedures with code not understood by the old server are doomed.

C.

Commented by: @hvlad

> And the term "Transportable Format" say's it is transportable between platforms, but it does not specify 'of the same versions'.

This is your own wrong interpretation

Claudio, am i right that this new gbak 2.1 functionality independent of "transportable" flag and will work with any backups kind ?

Commented by: @dyemanov

Claudio, while your v2.1 changes are welcome, they don't make the backup file backward compatible :-)
So I don't see much value in reopening this ticket. We're talking about different things.

Commented by: Claudio Valderrama C. (robocop)

Transportable only says that you won't have problems if you take the backup to a machine with different endianess. Trying to put as much as possible in an old server is orthogonal.
However, if the feature that was requested is different (and since I don't have an opinion on how useful or useless is the code I changed) then I don't care what's the final status of this tracker item.

Commented by: ohenri (ohenri)

Thank you all for your comments.

Indeed, I was not amused about the fast close of that ticket, but naturally I have to accept it, and I do.

But now, let me explain.

I tested FB 2, ok so far.
Then I upgraded PROD from FB153 to FB2. Ok so far.
Then I changed ODS to 11. Ok so far.

Then, some weeks later, problems arised, and I noted them into the bugtracker.
But they are very special, and I have to accept it will take time to correct them, if ever.

And so, how to fallback to FB 153?
Naturally by backup / restore as I did it in such cases since ever in all other DBMS I ever used.
It always worked as long as I didnt used new options.
But no more with FB, so I pumped the tables manually back into a FB153/ODS10.1 database. Hard work.

Then I run into other FB2-problems (poor performance) with another application, and again I needed to goback to FB153, and must do this by manual work since backup/resore does not work.

That's the reason why I placed this bug.

I know this is not really a discussion platform - so if you remove my last comment, it's ok for me.

Commented by: @dyemanov

Closed again as "Won't fix, by design". I don't think we can make the backup *file* readable by any GBAK version. Downgrade is supported via two other alternatives. This is not ideal, but I doubt we could offer anything better in the short term.

Commented by: Marius (marius)

I agree on some of the reasons for breaking the gbak support in FB2 and this item staying closed ;-)
However we do need the posibility to downgrade or even reverse a FB2 to FB1.5.4 for support and testing.
(the DB in question has accidently been converted to FB2 by one of our customers)

It would be very nice if there would be some guidelines explaining how to do this downgrade + some links to tools (if there are any needed).
I cannot find/download the GBak 2.1 and i don't even know how to use it..

We don't use any of the additional technical stuff from FB2, is there any risk we will lose data with a downgrade??