Forces all file writes to be flushed to disk before returning a success status to the Extract process. By default, the file system buffers the I/O because it is more efficient than flushing to disk with every operation. Generally, the performance benefits outweigh the small risk that data could be lost if the system fails after an I/O is confirmed successful, but before the buffer actually is flushed to disk. Use -f if this risk is unacceptable, with the understanding that it can compromise the performance of Oracle GoldenGate