Manually Creating Objects

Before adding an object to a group at the master definition site, you can manually create an identical object definition at each master site. Later, when you add the object to the group, Oracle can use the existing objects and avoid creating the object at each master site.

If the replicated object exists at other sites, then enable the Use Existing Object option. In this case, Oracle uses the existing objects at the master sites and does not create new objects. However, if you enable the Use Existing Object option and the object does not exist at the other master sites, Oracle creates the object automatically.

Manual creation of replication objects can help to minimize network traffic when you are configuring large replication environments. You might also want to consider this option when a master group contains tables with circular dependencies or a specific table contains a self-referential constraint.

When you choose to precreate replication objects, consider the following issues.

• When you choose to precreate a replicated table yourself, you are responsible for ensuring that the shape of the table (number, names, and data types of all table columns) is identical at all sites. Oracle raises an exception when a table at a master site is not the same shape as the table at the master definition site.

• When you choose to precreate a non-table replication object yourself, you are responsible for ensuring that the SQL definition of the object is identical at all sites. Oracle raises an exception when an object at a master site does not have the same SQL definition as the object at the master definition site.