The log buffer is the memory area that holds data to be written to
the log files on disk. Log buffer size is defined by the
The default size is 16MB. The contents of the log buffer are
periodically flushed to disk. A large log buffer enables large
transactions to run without the need to write redo log data to
disk before the transactions commit. Thus, if you have
transactions that update, insert, or delete many rows, increasing
the size of the log buffer saves disk I/O.