Migrate FB2.5 -> 4.0

[Maciej Luźniak]

I will immediately point out that I am not a firebird administrator, for that I have tasks that are related to administration.

The goal of the client is to migrate the database from version 2.5 to version 4.0. How to do it best?

Some steps I've already made like removing forbidden words like "LOCAL" which was in several places as a variable or table field name, or removing the suspend keyword in procedures without a return (in 2.5 it was a warning, and in 4.0 it's an error). I also tried to clean up the UDFs so that mechanisms don't use them, but use native FB functions. I have the impression that this was successful, because the recompilation of all metadata was successful and the operation fdb (2.5) -> fbk -> fbd (4.0) was successful and the base is visible in IBExpert as 4.0. The problem is unfortunately with the UDFs, which again have hundreds of dependencies, and the base in 4.0 does not allow modification of metadata using system tables. So I ask

1. What is your experience in upgrading firebird database version?
2. Ss the way I adopted (fdb (2.5) -> fbk -> fbd (4.0)) correct?
3. How can I detach unnecessary DLL files with UDFs from the 4.0 server, as they are currently causing many issues?

Any help and pointing me in the right direction would be appreciated.

The database itself is over 1.7 TB, so many of these processes are time consuming and I can't afford to test them all.

Regards,

Maciej Luźniak

[Dimitry Sibiryakov]

Maciej Luźniak wrote 05.10.2023 11:53:
> The goal of the client is to migrate the database from version 2.5 to version 4.0. How to do it best?

Almost the same way as migrating to a different DBMS:

1. Take the database's master-script and adapt it for a new server version.
2. Create a new database from this script on the new server and pump data from
the old server.
3. Perform full tests of applications to make sure that they still work.

If these steps were successful you can plan maintenance window for real
migration.

> 1. What is your experience in upgrading firebird database version?

It should not be done without cooperation with application developer because
some changes in application may be required as well.

> 2. Ss the way I adopted (fdb (2.5) -> fbk -> fbd (4.0)) correct?

Not in your case because, as you described, you had to change database structure.

> 3. How can I detach unnecessary DLL files with UDFs from the 4.0 server, as they
> are currently causing many issues?

They are not attached if they are not used so they won't be attached to the
new server.

--
WBR, SD.