The C API for the Berkeley DB Transaction subsystem was reworked in the 4.0 release as follows:

Historic functional interface Berkeley DB 4.X method
txn_abort DB_TXN->abort()
txn_begin DB_ENV->txn_begin()
txn_checkpoint DB_ENV->txn_checkpoint()
txn_commit DB_TXN->commit()
txn_discard DB_TXN->discard()
txn_id DB_TXN->id()
txn_prepare DB_TXN->prepare()
txn_recover DB_TXN->recover()
txn_stat DB_TXN->stat()

Applications calling any of these functions should update their calls to use the enclosing DB_ENV class handle's method (easily done as the first argument to the existing call is the correct handle to use).

As a special case, since applications might potentially have many calls to the txn_abort, txn_begin and txn_commit functions, those functions continue to work unchanged in the Berkeley DB 4.0 release.

In addition, the DB_TXN->stat() call has been changed in the 4.0 release to take a flags argument. To leave their historic behavior unchanged, applications should add a final argument of 0 to any calls made to DB_TXN->stat().