When a primary table is marked for replication, Replication Agent creates a shadow table to record the replicated operations. The shadow table has all the columns of the primary table, plus three columns that the Replication Agent creates for its use:
ra_tran_id_
ra_opid_
ra_img_type_
These column names are fixed, not generated; therefore,
the “ra_” portion of the column name
does not change when the value of the pdb_xlog_prefix parameter
changes.
If a primary table has a column with the same name as one of the Replication Agent shadow table columns, the table marking procedure fails. Replication Agent flags the conflicting column in the table-marking script and the pdb_setreptable command returns an error.
In this event, you must change the name of the conflicting column in the primary table in order to replicate changes to that table. After you change the name of the conflicting column, you can modify the table-marking script and run it manually to mark the primary table.
If you want to use the primary table’s original
column name in the replicate table, you can create a function string
in the replicate Replication Server to map the new column name in
the primary table to a different column name in the replicate table.
