The Subscription Resolution Engine (SRE) matches transaction rows with subscriptions. When it finds a match, it attaches a destination-database ID to each row. It marks only rows required for subscriptions, thereby minimizing network traffic. If no subscriptions match, the DIST thread discards the row data.
For each row, the SRE determines whether subscription migration occurs.
A row migrates into a subscription when its column values change so that the row matches the subscription and must be added to the replicate table.
A row migrates out of a subscription when its column values change so that it no longer matches the subscription and must be deleted from the replicate table.
When the SRE detects subscription migration, it determines which operation to replicate (insert, delete, or update) to maintain consistency between the replicate and primary tables.
