If the Oracle database is in the file system, the following parameter settings can increase I / O:
Set disk_asynch_io to false .... In the file system, use synchronization I / O to reduce the average wait time of the DB File Parallel Write event, and in the bare device, asynchronous I / O should be used, of course, whether the system is supported in advance. .
If the operating system supports the function directly written directly on the file system, set the parameter filesystemio_options to Directio. Otherwise, set to None (this is the default), which is visible in Oracle9i, hidden in Oracle8i.
If it is a UFS (UNIX File System), you can use the mincache = forcedirectio attribute when the Mount file system. If it is VXFS (Veritas file system), set to Direct.
Set a few DBWR processes DB_Writer_Processes
