I always rebuild the database - it doesn't take long (assuming your hardware is suitable for the size of database you have) and then you know exactly what you are dealing with, and you have the benefit of the rebuild.

If you don't, there is always the concern that any unexpected behaviour is something to do with running mismatching database format and server. You can also be sure that the second question iAnywhere Support will have is "Have you rebuilt the database?" (The first question is of course "Have you applied the latest ebf?")

Martin, each new SQL Anywhere version has typically new features that are only available with database files in the according file format. AFAIK, the Innsbruck docs are quite verbose for which new features an reload or upgrade is needed. As to the docs, it's however possible to run 10.x and 11.x databases with a v12 engine.

It difficult to state whether this is necessary for your particular needs, so the answer might be "Generally a rebuild is useful, but it depends".

Please note that there is a difference between

• just upgrading a database - i.e. just extend the system catalog (and some options, I guess) to the new format and
• rebuilding a database (i.e. unloading the complete schema and data and loading both in a newly generated database file with the new file format).

Only the latter will give you all possibilities of the new version.

AFAIK, with SA12, the pros and cons between a) leaving the database file at its state, b) upgrading and c) rebuilding are generally not different from the situation when SA 11 was introduced. - Only the particular feature sets are different.