The Zeroload Function's Inputs and Outputs

Input

The input to a Zeroload function is the name of a primary physical DBD which has been defined using DBDGEN. A Zeroload is not required, and should not be run, for any other kinds of databases.

Exclusive use databases and shared update (Fileshare) databases can be Zeroloaded. Shared read-only, Remote IMS, and User Exit databases cannot be Zeroloaded. An attempt to run a Zeroload for an incorrect Database Catalog type will result in an error.

An error message is issued if you attempt to Zeroload the following databases:

• The primary index for a HIDAM database. A primary index database is not required. The .IDX component of an MFIMS database is the equivalent of a primary index.
• Secondary index databases. These are created automatically when Zeroloading the primary database they index. A secondary index DBD which defines non-unique keys must be genned before Zeroloading the primary database.
• Databases defined as ACCESS=LOGICAL. The physical databases contain the required pointers to support logical relationships.
• GSAM databases. See the GSAM topic for complete details for GSAM databases.

Output

The output from a Zeroload function is the set of data files for the primary database and any secondary indexes defined. Any database calls or IMSDBU special functions can be made against a Zeroloaded database. A PCB with processing option 'L' is not required to load an initial segment to a database.