Hi,

Is a file expensive or a device, for a DMS tablespace?
Is there any other advantage for using device other than to by pass the file system cache?

Please help.

Thanks,
Db

In strict sense, using a device is a better option than using a file container .. But with today's advancements in storage technology, the difference is not big ... It is much more difficult to configure and manage device based DMS containers ... Therefore, the general recommendation is to use file containers ...

If you are on Windows , you may use the DB2NTNOCACHE registry variable for both SMS and DMS ..

If you are on V8.1.4 and above on AIX 5.2 (check the documentation for more detailed patch information), limited direct i/o support is available for SMS tablespaces but hopefully may get extended to DMS file containers sometime soon ...

Cheers
Sathyaram

It also depends on the nature of the application. If you have a data warehouse with a lot of table scans of the entire table, then devices have a slight advantage. Otherwise you will see very little or no increase in performance compared to using a file system.

Thanks a lot for the information.

-Db