The storage of changes in a persistent form gives replica data the same degree of integrity as the source data. If the system or network fails, full recovery is available through the recovery capabilities of the source and target DBMSs. In the event of lost replica data, re-synchronize replication using a DBMS restoration of the database containing the metabase tables.
To preserve data consistency, the Change Selector captures and keeps all changes made within one user transaction together, and it makes only committed changes visible to other components of the replication system. The updates for one table in a transaction are replicated at the same time with updates for other tables to properly maintain the inter-table relationships.