Applier Processing of Updates for Duplicate Records
Applier Processing of Updates for Duplicate Records
If mapped source and target tables contain duplicate records, the Applier processing of Updates for these duplicate records depends on the apply mode.
In Audit Apply mode, the Applier processes Updates for duplicate records correctly.
In Merge Apply mode, the Applier ends with an error when processing Updates for duplicate records.
In SQL Apply mode, the Applier processing of Updates for duplicate records depends on whether the updated columns are part of a virtual index:
If the updated column in duplicate records is part of a virtual index, the Applier updates all of the target duplicate records.
If the updated column in duplicate records is not part of a virtual index, the Applier always updates only one of the target duplicate records. This behavior results in data inconsistencies.
To avoid data inconsistencies between the source and target tables that might contain duplicate records, add a virtual index for the source columns that might be updated on the source.