Online Redo Log Files Size

The size of the redo log files can influence performance, because the behaviors of the database writer and archiver processes depend on the redo log sizes. Generally, larger redo log files provide better performance. Undersized log files increase checkpoint activity and reduce performance. However, small log files and frequent checkpoints reduce recovery time. So, if daily operational efficiency is more important than minimizing recovery time, then set online redo log files to a relatively large value. Hundreds of MB is a normal size for Oracle Hyperion Financial Management databases. But the preferred way to determine the size of redo log files is to enable FAST_START_MTTR_TARGET, and run a typical database workload for a while. Then run the following query to obtain the optimal size of redo logs.

SQL> select optimal_logfile_size from v$instance_recovery;

For more details about how to tune MTTR target and the size of online redo files, please refer to the Oracle Database Performance Tuning Guide.