Extraction groups and extraction maps define the extraction information for registered data sources and are required for CDC processing.

An extraction group defines the database instance, node location, and data source type. When you create a registration group, PowerExchange creates an extraction group with the same name. You can also manually add an extraction group.

An extraction group contains one or more extraction maps. An extraction map maps a data source. When you create a capture registration, PowerExchange creates an extraction map that includes the same columns and registration tag name as in the capture registration. PowerExchange assigns a unique name to the extraction map.

You can also manually add additional extraction maps for a capture registration. A user-defined extraction map includes the same columns and registration tag name as in its associated capture registration. PowerExchange assigns a unique name to a user-defined extraction map that includes the map name that you specified when you added the extraction map.

The DTLCAMAP file, on a z/OS system, or the CAMAPS file, on a non-z/OS system, contain extraction map information defined in the PowerExchange Navigator. The extraction group filters the data in the DTLCAMAP or CAMAPS file for display in the PowerExchange Navigator.

You can edit extraction maps to add change indicator (CI) and before image (BI) columns for data columns, and to add columns to or remove columns from extraction processing.

For a DB2 source, you can merge a data map with an extraction map. The extraction map uses the associated data map to map the change data.

To test an extraction map, run a database row test.