How Data Synchronization Is Tracked

To keep track of synchronization, each database server in the pair keeps track of the following information in its reserved page:

• The ID of the logical-log file that contains the last completed checkpoint
• The position of the checkpoint record within the logical-log file
• The ID of the last logical-log file sent (or received)
• The page number of the last logical-log record sent (or received)

The database servers use this information internally to synchronize data replication.