DDS concepts

DDS syntax for a simple logical file



Syntax for a Simple Logical File. An illustration of a DDS coding form that describes a simple logical file.

(1)
Comments (optional): Comments can appear on any line in DDS. They are identified by an asterisk in position 7.

(2)
File level (optional): File-level keywords appear before the record format name (RECORD1 on line 00040).

(3)
Record level (at least one is required): R in position 17 identifies RECORD1 as a record format name. In simple or multiple format logical files, the PFILE keyword is required for every record format. The record level continues until the first field is named.

(4)
Field level: Field names and field attributes are not required for logical files. See the topic for logical file positional entries for more information.

(5)
Key field level (optional): K in position 17 identifies the field as a key field. A K must be specified for each key field. Specify the key field level by repeating one or more field names (such as FIELDA) after the field-level specifications.

(6)
Select and omit levels (optional): S in position 17 identifies FIELDB as a select field. (O in position 17 identifies a field as an omit field.) The select and omit levels follow the key field level.

Notes:

  1. To form a multiple format logical file, specify more record formats within the file by repeating items (3) through (6), or specify more than one file on the PFILE keyword.


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