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STANDARD FILES
A standard file may have several types of records. Nevertheless, the sort criteria and keys must be on all the records. This ’common part’ is described once in the Segment number ’00’. The specific part of each record is described in a Segment number ’nn’. In generated programs, a record description will be made of the concatenation of the ’00’ and the appropriate ’nn’ segment descriptions. A data element used to identify the specific record type has to be defined on the common part : the CODE OF RECORD TYPE. This data element code is specified on the definition line of segment number ’00’; the appropriate value is coded on the definition line of the specific part segment. For a file that has only one type of record, a unique ’00’ segment is described.
TRANSACTION FILE
A transaction file is made of records that update a ’permanent’ file. A data element belonging to the common part of the file is used to identify the type of update being done (Creation, Modification, Deletion, or other cases). It is called the ACTION CODE. This Data Element code and values are indicated on the Definition line of the ’00’ Segment, in the ’structure code’ and ’action code’ fields. When each specific part Segment is defined, the rules concerning its presence or absence with each type of update are specified in the corresponding fields.