Apply a merge in one transaction

Context

A failed participant must not leave some records combined and others unchanged.

Decision

CRM applies the planned merge and calls application participants within one transaction; failures roll it back before a separate transaction records the failed attempt and reopens eligible plans.

Alternatives Considered

Update application references after CRM commits. A failed subscriber could leave references attached to absorbed records.

Commit stages and compensate. The chosen design requires atomicity rather than a sequence of reversal operations.

Consequences

Mistakes require manual repair because merging has no reverse operation. Other edits can wait on the rows a merge holds. Rollback restores the merge row to queued until failure settlement commits; job progress may still show running.