The placement of Extract depends on where the mining database is located. The mining database is the one where the logmining server is deployed.

• Local Extract: For a local deployment, the source database and the mining database are the same. The source database is the database for which you want to mine the redo stream to capture changes, and also where you deploy the logmining server. Because integrated capture is fully integrated with the database, this mode does not require any special database setup.

• Downstream Extract: In a downstream deployment, the source and mining databases are different databases. You create the logmining server at the downstream database. You configure redo transport at the source database to ship the redo logs to the downstream mining database for capture at that location. Using a downstream mining server for capture may be desirable to offload the capture overhead and any other overhead from transformation or other processing from the production server, but requires log shipping and other configuration.

  When using a downstream mining configuration, the source database and mining database must be of the same platform. For example, if the source database is running on Windows 64-bit, the downstream database must also be on a Windows 64-bit platform. See Configuring a Downstream Mining Database.

• Downstream sourceless Extract: In the Extract parameter file, replace the USERID parameter with NOUSERID. You must use TRANLOGOPTIONS MININGUSER. Extract obtains all required information from the downstream mining database. Extract is not dependent on any connection to the source database. The source database can be shutdown and restarted without affecting Extract.

  Extract will abend if it encounters redo changes that require data to be fetched from the source database.

  To capture any tables that are listed as ID KEY in the dba_goldengate_support_mode view, you need to have a FETCHUSERID or FETCHUSERIDALIAS connection to support the tables. Tables that are listed as FULL do not require this. We also need to state that if a customer wants to perform SQLEXEC operations that perform a query or execute a stored procedure they cannot use this method as it is incompatible with NOUSERID because SQLEXEC works with USERID or USERIDALIAS.

For an Oracle source database, you can run Extract in either integrated extract or classic extract mode.

Although you can use the classic extract mode, it is recommended that you use the integrated extract mode because classic extract has been deprecated and is not being enhanced for any future releases. It will be desupported in future releases and any classic extract configuration will need to be migrated to integrated extract.

The method that you use determines how you configure the Oracle GoldenGate processes and depends on such factors as:

• the data types involved

• the database configuration

• the version of the Oracle Database