Parallel Scan Support

Replication Agent for Oracle allows you to run multiple scanner threads in parallel to read from transaction logs. Parallel scan is supported only with the Oracle LogMiner Log Reader component. Parallel scanners cannot be used to replicate tables containing large object (LOB) datatypes.

For a parallel scan, include a single Replication Agent process with multiple scanner threads to read from the Oracle transaction logs. Each thread that reads data records from the next batch of Oracle transaction log is sorted in a round-robin fashion. For example, a single scanner reads a batch of log records and sends them to the operation processor thread, which then reads the next batch while the next scanner sends its batch to the operation processor thread.

• lr_parallel_scan
  (Oracle only) Determines whether Replication Agent can run multiple Oracle LogMiner scanners in parallel or whether a single scanner thread is used, relying on the Oracle LogMiner Continuous Mine option.
• lr_parallel_scan_range
  (Oracle only) The maximum number of system change numbers (SCN) processed by each Oracle LogMiner scanner, when parallel scan is enabled, that is, when lr_parallel_scan is true.
• lr_parallel_scanner_count
  (Oracle only) The maximum number of Oracle LogMiner scanners running in parallel, when parallel scan is enabled, that is, when lr_parallel_scan is true.
• lr_parallel_scan_queue_size
  (Oracle only) The maximum scan queue size of each single LogMiner scanner, when parallel scan is enabled, that is, when lr_parallel_scan is true.