The DB2 database server logs changes to rows in DB2 tables as they occur. The information written to the transaction log includes copies of the data before and after the changes. In DB2, these records are known as undo and redo records. Control records are written for commits and aborts. These records are translated to commits and rollbacks.
The DB2 log consists of a series of data sets. Replication Extract uses these log data sets to identify DB2 data changes. Since DB2 writes change records to the active log as they occur, Replication Extract can process the log records immediately after they are entered.
