Requirements for Automatic Conflict Detection and Resolution
Supplemental logging is required to ensure that each row LCR has the information required to detect and resolve a conflict. Supplemental logging places additional information in the redo log for the columns of a table when a DML operation is performed on the table. When you configure a table for Oracle GoldenGate conflict detection and resolution, supplemental logging is configured automatically for all of the columns in the table. The additional information in the redo log is placed in an LCR when a table change is replicated.
Extract must be used for capturing. Integrated Replicat or parallel Replicat
in integrated mode must be used on the apply side. LOGALLSUPCOLS
should
remain the default.
There is a hidden field
KEYVER$$
of type timestamp that is optionally added to the
DELETE TOMBSTONE
table. This field is required for EARLIEST
TIMESTAMP
, DELETE ALWAYS WINS
, and SITE
PRIORITY
resolution and it also exists in the base table. The existence of
the field in the base table needs to be provided in the trail file metadata as a flag or
token.
Primary Key updates is also supported in the DELETE TOMBSTONE
table. An
entry is inserted into the DELETE TOMBSTONE
table for the row of the
original key value (before image). The logic in the Extract which matches inserts in the
DELETE TOMBSTONE
table to deletes also needs to be matched to PK
updates, or unique key (UK) with at least one non-nullable field, if there is no PK.
Site priority needs support from the Replicat, both the parameters are implemented and the setting is passed to the apply.