OS_FILE_CACHE_BUFFERING option

Controls use of file system buffering.

ON, OFF

Can be set for the PUBLIC group only. You must shut down the database and restart it for the change to take effect. DBA permissions are required to set this option.

OFF; default affects newly created databases only.

This performance option is available on Solaris UFS file systems and Windows file systems only. It does not affect databases on raw disk.

Setting OS_FILE_CACHE_BUFFERING = OFF prevents file system buffering for IQ Store files. Turning off file system buffering saves a data copy from the file system buffer cache to the main IQ buffer cache. Usually this reduces paging caused by competition for memory between the IQ buffer manager and the operating system’s file system buffer. When it reduces paging, this option improves performance. However, you need to be aware of one exception. If the IQ page size for the database is less than the file system's block size (typically only in the case in testing situations) performance decreases, especially during multiuser operation.

You may need to experiment with this option to determine the best setting for different conditions. You can change the option setting freely, but you must restart the database for the new setting to take effect.