For archived logs, Express CDC attempts to identify a primary copy and a secondary copy of each log that it must read. Express CDC identifies the primary and secondary archived log destinations based on the order of the archive destination numbers, where an archive destination number is the

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value in an Oracle LOG_ARCHIVE_DEST_

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parameter. The primary destination is the destination that 1) contains available logs that are suitable for PowerExchange use and 2) has the lower

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value compared to any other destination with available archived logs. You can override this behavior by specifying the ARCHIVEDEST parameter in the READER statement of the Express CDC configuration file.

If you specify MODE=ACTIVE in the READER statement, you can use any of the following optional parameters to filter active redo logs or archived log destinations:

For more information, see READER Statement.

In both ACTIVE and ARCHIVEONLY modes, PowerExchange Express CDC uses the ARCHIVEDEST parameter to filter archived log destinations, as follows:

If you specify MODE=ARCHIVECOPY in the READER statement, the PowerExchange Express CDC log reader reads copies of the archived redo logs that are located on a file system. You must specify the DIR parameter to identify the base directory that includes the copies of the archived redo logs. To filter the subdirectories under the base directory that the log reader scans and the copies of the archived log files in these subdirectories, also specify the FILE parameter with masks for the subdirectory names, log file names, or both.