5.7.6. Updating CDC after Schema Changes

If the schema for an existing CDC installation has changed, the CDC configuration must be updated to match the new schema configuration. If this step is not completed, then the correct information will not be extracted from the source tables into the CDC tables.

Schema changes should therefore be performed as follows:

  1. Stop the replicator using trepctl offline:

    shell> trepctl offline
  2. Change the schema definition within Oracle.

  3. If multiple tables have been changed, update the setupCDC.conf file so that the delete_publisher variable is set to one. This will ensure that the publisher is dropped and recreated for the entire table set.

    • To update multiple tables, the entire setup process must be started again; run the setupCDC.sh command, using the original configuration file, but with the delete_publisher set to 1:

      shell> setupCDC.sh setupCDC.conf
    • If only one table has changed, or you are adding only a single table, this can be specified on the command-line:

      shell> updateCDC.sh setupCDC.conf sampletable
  4. Put the replicator back online with trepctl online:

    shell> trepctl online

To add a new table to an existing configuration:

  1. Stop the replicator using trepctl offline:

    shell> trepctl offline
  2. Update the configuration using updateCDC.sh, supplying the new table name.

    shell> updateCDC.sh setupCDC.conf newtable

    If you have used a specific tables file (i.e. with specific_tables=1 in the configuration file, make sure that you add the table to the table file.

  3. Put the replicator back online with trepctl online:

    shell> trepctl online