The application should never explicitly call txn_commit,
txn_abort or txn_begin, as those calls are replaced by
calls into the Tuxedo transaction manager. For the same reason, the
application will always specify a transaction argument of NULL to the
Berkeley DB functions that take transaction arguments (e.g., DB->put or
DB->cursor).
Otherwise, your application should be unchanged.
Is it possible to mix XA and non-XA transactions?
Yes. It is also possible for XA and non-XA transactions to co-exist in
the same Berkeley DB environment. To do this, specify the same environment to
the non-XA DBENV->open calls as was specified in the Tuxedo
configuration file.
How does Berkeley DB recovery interact with recovery by the transaction
manager?
When the Tuxedo recovery calls the Berkeley DB recovery functions, the standard
Berkeley DB recovery procedures occur, for all operations that are represented
in the Berkeley DB log files. This includes any non-XA transactions that were
performed in the environment. Of course, this means that you can't use
the standard Berkeley DB utilities (e.g., db_recover) to perform
recovery.
Also, standard log file archival and catastrophic recovery procedures
should occur independently of XA operation.