DDL Replication with Multiple Replication Agents

You can configure each Replication Agent instance to replicate all DDL operations or no DDL operations in the primary database.

In a Replication Agent group, you can also configure each Replication Agent instance to replicate:

DDL operations for all objects marked for replication by the instance
DDL operations for all objects marked for replication by the instance and DDL operations for objects not marked for replication by any instances

To avoid DDL synchronization errors with multiple Replication Agents, use these keywords with the pdb_setrepddl command:

all specifies that all DDL operations are to be replicated by the instance.
marked specifies that only DDL operations for objects that have been marked for replication by the instance are to be replicated.
unmarked specifies that DDL operations for objects that have not been marked for replication by any instance are to be replicated. Nonschema DDL operations are also replicated by an instance that specifies this keyword.

Example

A Replication Agent group containing three instances replicates DDL operations performed on these tables in the primary database:

table_A is marked for replication by instance ra_instance_1.
table_B is marked for replication by instance ra_instance_2.
table_C is marked for replication by instance ra_instance_3.
table_D is not marked for replication by any instance.

The Replication Agent instances use the pdb_setrepddl command to specify which DDL to replicate:

ra_instance_1>pdb_setrepddl enable, marked
ra_instance_1>pdb_setrepddl enable, unmarked
ra_instance_2>pdb_setrepddl enable, marked
ra_instance_3>pdb_setrepddl enable, marked

The DDL is replicated as follows:

Replication Agent Instance	DDL Replicated
`ra_instance_1`	DDL for `table_A`, `table_D`, and nonschema DDL operations
`ra_instance_2`	DDL for `table_B`
`ra_instance_3`	DDL for `table_C`