Oracle CDC V2 Connector > Oracle CDC administration > Handling changes to extraction maps
  

Handling changes to extraction maps

If you add or drop columns in an Oracle source table, you must create a new capture registration. PowerExchange generates an associated extraction map by default. Use the generated extraction map instead of creating a user-defined extraction map. The PWX CDC Reader on the Oracle CDC V2 Connector system will retrieve information from the new generated extraction map.
To switch to the new table definition and preserve access to previously captured data, you must perform several steps in both the PowerExchange and Oracle CDC Connector environments.
Note: You do not need to perform these steps if you selectively capture change data for a subset of columns, and the DDL changes do not affect any of these columns.
  1. 1. Stop data change activity on the Oracle source table.
  2. 2. Verify that any change data that was captured under the current table definition has completed Oracle CDC Connector extraction processing. Then stop all mapping tasks that extract change data for the table.
  3. 3. Shut down the PowerExchange Logger for Linux, UNIX, and Windows.
  4. 4. In the PowerExchange Navigator, open the original capture registration and set its status to History.
  5. 5. Drop the supplemental log group for the table.
  6. 6. Add or drop columns in the source table.
  7. 7. In the PowerExchange Navigator, create a new capture registration for the table that reflects the column changes. Include the following settings:
  8. 8. Warm start the PowerExchange Logger.
  9. 9. Alter the target table to reflect the source table changes, if necessary.
  10. 10. In Data Integration, for each mapping that includes the source table, perform the following steps:
  11. 11. If necessary, rematerialize the target tables.
  12. 12. In the mapping task, set a time-based restart point that coincides with the time of target rematerialization or let the mapping task restart from the last checkpoint that was recorded in the state table on the target.
  13. 13. Resume change activity on the source table.
  14. 14. Start the mapping task again.