Designating an Alternate Key for a Replicated Table

Oracle must be able to uniquely identify and match corresponding rows at different sites during data replication. Typically, Oracle replication uses the primary key of a table to uniquely identify rows in the table. When a table does not have a primary key, you must designate an alternate key. This alternate key can be a column or set of columns that Oracle can use to uniquely identify rows in the table during data replication.

When you create a new master group that has a table that does not have a primary key, or attempt to add a table that does not have a primary key to a master group, the Create Master Group Wizard automatically displays the Set Alternate Key Columns page so that you can identify an alternate identity column or set of columns for the replicated table.