Configuring Classic Extract for ADG Mode

To configure Classic Extract for ADG mode, follow these steps as part of the overall process for configuring Oracle GoldenGate, as documented in Additional Configuration Steps for Using Classic Capture.

Enable supplemental logging at the table level and the database level for the tables in the primary database using the ADD SCHEMATRANDATA parameter. If necessary, create a DDL capture.)
When Oracle GoldenGate is running on a different server from the source database, make certain that SQL*Net is configured properly to connect to a remote server, such as providing the correct entries in a TNSNAMES file. Extract must have permission to maintain a SQL*Net connection to the source database.
On the standby database, use the Extract parameter TRANLOGOPTIONS with the MINEFROMACTIVEDG option. This option forces Extract to operate in ADG mode against a standby database, as determined by a value of PRIMARY or LOGICAL STANDBY in the db_role column of the v$database view.

Other TRANLOGOPTIONS options might be required for your environment. For example, depending on the copy program that you use, you might need to use the COMPLETEARCHIVEDLOGONLY option to prevent Extract errors.
On the standby database, add the Extract group by issuing the ADD EXTRACT command specifying the number of threads active on the primary database at the given SCN. The timing of the switch depends on the size of the redo logs and the volume of database activity, so there might be a limited lag between when you start Extract and when data starts being captured. This can happen in both regular and RAC database configurations.