DEFINE ALTERNATEINDEX

Parameters:

MFJAMS uses the parameters described in the following table. All other parameters are ignored.

NAME(data-set-name): Name of the data set. This parameter is required.
KEYS(length offset): Length and offset, relative to 0, of the alternate key field. The offset must be within the first 4,096 bytes of the record. Length plus offset must not exceed the maximum length of the record. The default is KEYS(64 0).
UNIQUEKEY: Each alternate key value in the records is unique.
NONUNIQUEKEY: The alternate key values may contain duplicates.
RELATE(data-set-name): Name of a cataloged VSAM data set to which the alternate index is to be related.

UNIQUEKEY and NONUNIQUEKEY are mutually exclusive. NONUNIQUEKEY is the default.
Because MFJAMS automatically reindexes the data set, the BLDINDEX parameter is assumed even if it is not specified.
You can create up to seven alternate indices in one invocation of MFJAMS. Enter separate commands for each index. MFJAMS performs a single reindexing operation for all the alternate indices.
MFJAMS does not support the Micro Focus split-key and key-compression features. MSS cannot open a VSAM data set that uses either of these features.