COMMIT_WAIT is an advanced parameter used to control when the redo for a commit is flushed to the redo logs.
If the parameter is set to FORCE_WAIT, the default behavior ( immediate flushing of the redo log buffer with wait) is used. If this is a system setting, the session level and transaction level (COMMIT_WRITE) options will be ignored. If this is a session level setting, the transaction level options will be ignored. If COMMIT_WAIT is altered after it has been set, then the FORCE_WAIT option is no longer valid.