Вот здесь мне рассказывали про транзакции:
/topic/62536&pg=3
А вообще посмотри еще по хелпу, в Гетце... Кстати:
Хелп А2К BeginTrans, CommitTrans, Rollback Methods

Notes
In a Microsoft Jet workspace, transactions are logged in a file kept in the directory specified by the TEMP environment variable on the workstation. If the transaction log file exhausts the available storage on your TEMP drive, the database engine triggers a run-time error. At this point, if you use CommitTrans, an indeterminate number of operations are committed, but the remaining uncompleted operations are lost, and the operation has to be restarted. Using a Rollback method releases the transaction log and rolls back all operations in the transaction.