SQL Server 7.0 (cont’d)
Immediate updating subscriber
- Can update data, synchronizing with publisher via 2PC
- Uses triggers to capture updates (Not For Replication disables trigger for updates from the publisher)
- Subscriber sends before/after row timestamp. Publisher checks row didn’t change since subscriber’s current copy
- Publisher then forwards updates to other subscribers
Access control lists protect publishers from unauthorized subscribers
Merge replication- described later