Replication of alter table: Limitations

When Adaptive Server performs an alter table ... add column_name default ... statement, the server creates a constraint for the default value using the objid.

After Replication Server replicates this statement, the standby Adaptive Server creates the same constraint but with a different objid.

If the constraint is later dropped at the primary using alter table ... drop constraint ... , the statement cannot be performed at the warm standby because the objid is not the same.

To drop the constraint at both the primary and standby databases, execute either of these statements at the primary database:

alter table table_name
		...
		replace column_name default null

```
alter table table_name
		...
		drop constraint constraint_name
```
This statement shuts down the DSI. Execute the same command at the standby database with the corresponding objid, and then resume the connection to the DSI, skipping a transaction.