1. Oracle GoldenGate Classic Architecture Documentation
  2. Prepare
  3. Prepare Your Database for Oracle GoldenGate Classic Architecture
  4. PostgreSQL
  5. Preparing the Database for Oracle GoldenGate
  6. Preparing Tables for Processing
  7. Disabling Triggers and Cascade Constraints on the Target

Disabling Triggers and Cascade Constraints on the Target

If Oracle GoldenGate is configured to capture DML operations from source tables that occur due to trigger operations or cascade constraints, then disable the triggers and cascade delete and cascade update constraints on the target tables.

If not disabled, the same trigger or constraint gets activated on the target table and becomes redundant because of the replicated data. Consider the following example, where the source tables are emp_src and salary_src and the target tables are emp_targ and salary_targ

  1. A delete is issued for emp_src.

  2. It cascades a delete to salary_src.

  3. Oracle GoldenGate sends both deletes to the target.

  4. The parent delete arrives first and is applied to emp_targ.

  5. The parent delete cascades a delete to salary_targ.

  6. The cascaded delete from salary_src is applied to salary_targ.

  7. The row cannot be located because it was already deleted in step 5.

In the Replicat MAP statements, map the source tables to appropriate targets, and map the child tables that the source tables reference with triggers or foreign-key cascade constraints. Triggered and cascaded child operations must be mapped to appropriate targets to preserve data integrity. Include the same parent and child source tables in the Extract TABLE parameters.