1. Oracle GoldenGate Classic Architecture Documentation
  2. Administer
  3. Data Management
  4. Oracle: DDL Replication
  5. Managing the DDL Replication Environment
  6. Maintaining the DDL History Table

Maintaining the DDL History Table

You can purge the DDL history table to control its size, but do so carefully.

The DDL history table maintains the integrity of the DDL synchronization environment. Purges to this table cannot be recovered through the Oracle GoldenGate interface.

  1. To prevent any possibility of DDL history loss, make regular full backups of the history table.

  2. To ensure that purged DDL can be recovered, enable Oracle Flashback for the history table. Set the flashback retention time well past the point where it could be needed. For example, if your full backups are at most one week old, retain two weeks of flashback. Oracle GoldenGate can be positioned backward into the flashback for reprocessing.

  3. If possible, purge the DDL history table manually to ensure that essential rows are not purged accidentally. If you require an automated purging mechanism, use the PURGEDDLHISTORY parameter in the Manager parameter file. You can specify maximum and minimum lengths of time to keep a row.

Note:

Temporary tables created by Oracle GoldenGate to increase performance might be purged at the same time as the DDL history table, according to the same rules. The names of these tables are derived from the name of the history table, and their purging is reported in the Manager report file. This is normal behavior.