1. Oracle GoldenGate Microservices Documentation
  2. Administer
  3. Error Management
  4. Automatic Conflict Detection and Resolution
  5. About Automatic Conflict Detection and Resolution
  6. Delete Always Wins Timestamp CDR

Delete Always Wins Timestamp CDR

DELETE ALWAYS WINS is enabled through the field ADDITIONAL_OPTIONS in both DBMS_GOLDENGATE_ADM procedures ADD_AUTO_CDR() and ALTER_AUTO_CDR(). This is again a delete conflict resolution method, which is not using latest timestamp resolution, therefore, versioning is needed. Turning on DELETE ALWAYS WINS automatically turns on versioning, which adds a new hidden column KEYVER$$ (version number) of type timestamp. A new flag value is also added to acdrflags_kqldtvc to indicate DELETE ALWAYS WINS usage. This field is also added to the DELETE TOMBSTONE table. The same versioning issues exist as the EARLIEST TIMESTAMP resolution.

Example:

Key Version kv and Timestamp ts

Database 1: insert tab1 key1 kv1 ts1

Database 2: delete tab1 key1 kv1 ts1

Insertion to DELETE TOMBSTONE table key1 kv1 ts1

Database 1: insert tab1 key1 kv2 ts2

Without using the key version, the insert would be ignored, the delete always wins. As the key version is used, you know that kv2 is not the version of the row that was deleted and the insert succeeds.