The two types of transactions that can occur in HiRDB are transactions that occur separately at each back-end server (forming transaction branches) and transactions that combine them (called global transactions). Normally, Datareplicator links to one transaction branch at a time; therefore, immediately after a transaction branch is imported, data integrity cannot be guaranteed for a global transaction.

When the import transaction synchronization facility is used, data integrity for each global transaction that has occurred at the source HiRDB can be guaranteed when transaction branches are imported.