Altering a Replicated Table in a Classic Replication Scheme

You can use ALTER TABLE ... ADD COLUMN or ALTER TABLE ... DROP COLUMN statements to add or drop columns on the master database in a classic replication scheme.

The ALTER TABLE operation is replicated to alter the subscriber databases. These are the only ALTER TABLE clauses that are replicated in a classic replication scheme.

If you use ALTER TABLE on a database configured for bidirectional replication, first stop updates to the table on all of the replicated databases and confirm all replicated updates to the table have been received by the databases before issuing the ALTER TABLE statement. Do not resume updates until the ALTER TABLE operation has been replicated to all databases. This is necessary to ensure that there are no write operations until after the table is altered on all databases.

Note:

You can use the ttRepSubscriberWait built-in procedure or monitoring tools described in Managing Replication to confirm the updates have been received and committed on the databases.

Also, if you are running a number of successive ALTER TABLE operations on a database, you should only proceed with the next ALTER TABLE after you have confirmed the previous ALTER TABLE has reached all of the subscribers.

Note:

You can use the ALTER TABLE statement to change default column values, but the ALTER TABLE statement is not replicated. Thus, default column values need not be identical on all nodes.