| Property | Description |
|---|---|
| Parameter type | Boolean |
| Default value | true |
| Modifiable | No |
| Range of values | true | false |
| Basic | No |
DISK_ASYNCH_IO controls whether I/O to datafiles, control files, and logfiles is asynchronous (that is, whether parallel server processes can overlap I/O requests with CPU processing during table scans). If your platform supports asynchronous I/O to disk, Oracle recommends that you leave this parameter set to its default value. However, if the asynchronous I/O implementation is not stable, you can set this parameter to false to disable asynchronous I/O. If your platform does not support asynchronous I/O to disk, this parameter has no effect.
If you set DISK_ASYNCH_IO to false, then you can increase DB_WRITER_PROCESSES or use DBWR_IO_SLAVES to simulate asynchronous I/O.
See Also:
Oracle Database Performance Tuning Guide for more information about choosing between multiple DBWR processes and I/O slaves