Informatica recommends that you install and run PowerExchange on the machine with the physical standby database. A PowerExchange installation is not required on the primary database machine.

The physical standby database can use real-time apply with standby redo logs or apply data directly from the archived logs only.

The physical standby database can be open with read-only access, or it can be not open, such as when started with the mount option.

PowerExchange Express CDC supports any configuration of primary and standby databases that Oracle Data Guard supports, including databases in RACs that use ASM. The number of nodes on the primary and standby systems do not need to match.

In the PowerExchange Navigator client, create a registration group and capture registrations for the Oracle source instance and tables on the primary system from which the changes originate.

In the dbmover.cfg configuration file on the standby system, configure the following statements to point to the Oracle instance on the primary system:

The ORACOLL parameter in the ORAD CAPI_CONNECTION statement
The DFLTINST parameter in the CAPX CAPI_CONNECTION statement
The first positional parameter,
collection_id
, in the ORACLEID statement

In the Express CDC pwxorad.cfg configuration file on the standby system, define the following statements if the standby database is open for read-only access:

Define a DATABASE statement that provides connection information for the standby system.
If the primary database is a RAC database, define a RAC statement. PowerExchange verifies the RAC MEMBERS parameter value against the number of threads on the standby or archived redo logs. The RAC MEMBERS value should be equal to the number of threads.

Define a DATABASE statement that provides connection information for the primary system. PowerExchange requires this connection to access the Oracle data dictionary on the primary system.
Define a STANDBY statement that provides connection information for the standby system. The user that you specify for the STANDBY connection must have SYSDBA authority to access the fixed views and monitor the Data Guard apply progress in a database that is not open.

When the standby database is

not

open for read-only access, Oracle might not progress apply processing beyond the tip of the last archived log, even if more recent changes are available in the standby redo logs. To get near-real-time capture processing, add APPLYACTIVE=Y in the STANDBY statement. PowerExchange will then read change data from the standby redo logs up to the highest of the low SCN values in the standby logs for all threads.

PowerExchange CDC captures data up to the current database SCN, or apply SCN, for a physical standby database. If Oracle stops applying data for some reason, for example, because of a log gap, PowerExchange change capture processing stalls and waits for the apply process to resume with message PWX-36098.