Autocorrection

Replication Agent now supports the autocorrection feature of Replication Server that prevents failures caused by missing or duplicate rows in a replicated table. In Replication Server, the set autocorrection command corrects discrepancies that may occur during materialization by converting each update or insert operations into a delete followed by an insert. A new Replication Agent command, ra_set_autocorrection, has been introduced to support the set autocorrection command of Replication Server. Use the ra_set_autocorrection command to set autocorrection on or off for one or all marked tables, and to return the autocorrection status. See the Replication Agent 15.5 Reference Manual.

When you set autocorrection on a marked table using ra_set_autocorrection, Replication Agent sends all columns of this table, instead of sending only those columns that have changed in the update statement, to Replication Server.

The primary databases that support auto correction are:

• Oracle – the auto correction feature cannot work on LOB, LONG, LONG RAW, and user-defined type columns because of Oracle limitations for redo log recording.

  To support autocorrection, the default Oracle logging behavior is changed to enable supplemental logging for all columns. The pds_username must have the ALTER ANY TABLE privilege to execute the commands for enabling supplemental logging.

• Microsoft SQL Server

• IBM DB2 UDB

See “Replication Server set autocorrection command” for each of the database, in the Replication Agent 15.5 Primary Database Guide.

The limitations of this feature are:

• You cannot set autocorrection for unmarked tables.

• Replication Agent cannot alter the autocorrection setting for replication definitions.