at our customers site there's currently a migration going on from an Oracle 10g RAC to a 11g RAC.
Its all in testing mode right now so we can redo things as often as we want, but at some point of course we need a bullet-proof migration.
We need to completely migrate the database, including the history and all workspaces.
Afaik this should be possible using the full database export/import.
However, we are facing several issues. The first ones are fixable, though they are strange. They are not really the scope of this question, but maybe someone has an idea though:
We're having some triggers on version enabled tables that convert a value inserted in one column into another representation for another column of the table.
For some odd reason after the migration has been done the table is in LWEV mode with a failed DROP on the respective procedure for one of those triggers (DROP failed due to too long name).
We have no clue where that DROP is issued from at all. RecoverMigratingTable helps and we then can re-add the trigger.
What we noticed however is that in the 11g version the trigger is not represented by an procedure anymore. Is that the reason why the upgrade procedure to 11g issues a drop?
Now for the actual question: we have for one row some old workspace difference popping up.
The difference already has been merged in the database state from which the new database is migrated. In the source (production) database issueing a SELECT on the _DIFF view for the respective table gives 0 rows. Issueing the same SELECT on the migrated database given 3 rows for one entry. Comparing things with the _HIST view entries, DiffBase and WS1 rows correctly reflect the current state of that entry, however the row for WS2 is some very old state from December 2011.
If the user now edits that row in one of the workspaces WS1 or WS2 we suddenly receive 6 rows for that entry because the new difference is also determined.
Is it known how something like that can happen? We definitely need to understand the reasons because else we can't be sure that problems like that migth also occur at other places.
Thanks in advance for any input!