Jason,

In the end we decided to take everything in easy stages: going from IB4.xx/6.x to FB2.0/2.5 on 64-bit was just far too much in one go.

1. IB xxx -> FB1.0 all dialect 1 : straightforward. FB runs in the same environment.

2. Modified a copy of FB1.0 to make datatypes match those in dialect 3; data migration to FB1.5 courtesy of a data pump (DWB4) to match columns in tables and migrate in one go.

3. As we do not have the volumes of data whereby we would benefit from 64-bit addressing, we have stayed with 32-bit. We did initially try XP Pro-64bit as a test, but there were many probs with the app - see Evgeniy Rhyzkov paper on 64-bit apps and it is easy to see why there were probs (contact evg@...) - hence another reason to stay 32bit.

4. Still in 32-bit, the app still needed some changes to accommodate the dialect 3 datatypes. Thus, once in FB1.5, we do not see an easy path back to the FB1.0/IB4/6 scenario - that has to be dropped.

5. -> 64-bit and FB2.x,  I would suggest is another stage after having ensured FB1.5 is totally stable - shortcutting the stages is not an option. Every step must be safe and secure, robust and reliable.

Do read Evgeniy's paper. HTH

Kind Regards,Brian Gooch 

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