Setting the database instance to ARCHIVELOG mode

CDC Replication requires uninterrupted access to Oracle redo logs. Therefore, you must enable the archiving of Oracle redo logs.

Make sure that the source database instance is operating in ARCHIVELOG mode. This lets CDC Replication read data from archived Oracle redo logs instead of online redo logs, in the event that excessive latency occurs during mirroring. To set the source database instance to ARCHIVELOG mode, contact your database administrator. You can also verify if archive logging is enabled for the source database by issuing the following SQL statement: select log_mode from v$database; If archive logging is enabled, the returned value will be instance to ARCHIVELOG mode. For more information, see your Oracle documentation. CAUTION: If you do not set the database instance to ARCHIVELOG mode, you may experience data loss.

CDC Replication must have direct access to the archive log files. You can install the CDC Replication software on the same node that has access to the archive log files. However, if your database instance is managed by Oracle Automatic Storage Manager (ASM), then you can install the CDC Replication software on any node. Please be aware that reading archive and redo logs from ASM can be significantly slower than reading the logs through the file system. If the database produces high volumes of logs, you should consider multiplexing the logs by configuring a log destination outside ASM.