During Direct Path operations the data is asynchronously read from the database files. At some stage the session needs to make sure that all outstanding asynchronous I/O have been completed to disk. This can also happen if during a direct read no more slots are available to store outstanding load requests (a load request could consist of multiple I/Os).
Wait Time: 10 seconds. The session will be posted by the completing asynchronous I/O. It will never wait the entire 10 seconds. The session waits in a tight loop until all outstanding I/Os have completed.
| Parameter | Description |
|---|---|
|
descriptor address |
This is a pointer to the I/O context of outstanding direct I/Os on which the session is currently waiting |
|
first dba |
The dba of the oldest I/O in the context referenced by the descriptor address |
|
block cnt |
Number of valid buffers in the context referenced by the descriptor address |
See Also:
Oracle Database Performance Tuning Guide for more information about this wait event