Modifying Physical Database Definitions › Changing the Access Method of a File

Changing the Access Method of a File

Procedure

You can change the format of database files from non-VSAM to VSAM and vice versa. To complete this process, you need to:

1. Expand the page size of the file's area, if necessary
2. Alter the file definition to change its access method (and optionally to specify a new database name or other location information) and generate, punch, and link all DMCLs in which the file's segment is included.
3. Allocate a new VSAM or non-VSAM data set, as described in Allocating and Formatting Files.
4. Make the area to be processed unavailable for update under the central version.
5. Copy the old VSAM or non-VSAM file to the new data set.
6. Make the new DMCLs and file available to the runtime environment.

Steps 1 and 5 are discussed next.