This event occurs in the DBWR. It indicates the time that DBWR spends waiting for I/O completion.
If asynchronous I/O is available, then the db file asynch I/O submit wait event captures any time spent in submitting I/Os to the underlying storage.
When asynchronous I/O is not available, db file parallel write captures the time spent during submit and reap.
Wait Time: While there are outstanding I/Os, DBWR waits for some of the writes to complete. DBWR does not wait for all of the outstanding I/Os to complete.
| Parameter | Description |
|---|---|
| requests | This indicates the total number of I/O requests, which will be the same as blocks |
| interrupt | |
| timeout | This indicates the timeout value in hundredths of a second to wait for the I/O completion. |
Oracle Database Internal Mechanism 