Updated: Sep 21, 2018
The following listing of the Oracle 10g v$system_event wait events can be used as a reference for any version of Oracle’s wait class. For instance, a db file parallel read wait is considered a User I/O on any version of Oracle. Some versions will not show all of these waits; if the wait does appear, however, its categorization will match this table. It is a useful reference guide when discussing waits with your DBA.