4.2.9 RECORD KEY Clause
The RECORD KEY clause (Format 2) specifies the data item within the record
that is the prime RECORD KEY for an indexed file. The values contained in
the prime RECORD KEY data item must be unique among records in the file.
-
data-name-2
-
The prime RECORD KEY data item. It must be described as an
alphanumeric item within a record description entry associated with
the file.
X As an IBM extension, data-name-2 can be numeric, numeric-edited,
X alphanumeric-edited, alphabetic, floating-point (both external and
X internal), or a DBCS data item. The key is treated as an alphanumeric
X item for the input and output statements for the file named in the
X SELECT clause. When you specify data-name-2 as a DBCS data item, a
X key specified on the READ statement must also be a DBCS data item.
Data-name-2 must not reference a group item that contains a variable
occurrence data item. Data-name-2 can be qualified.
X As an IBM extension, if the indexed file contains variable-length
X records, data-name-2 need not be contained within the first "x"
X character positions of the record, where "x" equals the minimum record
X size specified for the file. That is, data-name-2 can be beyond the
X first "x" character positions of the record, but this is not
X recommended.
X Data-name-2 cannot be a windowed date field.
The data description of data-name-2 and its relative location within
the record must be the same as those used when the file was defined.
If the file has more than one record description entry, data-name-2 need
only be described in one of these record description entries. The
identical character positions referenced by data-name-2 in any one record
description entry are implicitly referenced as keys for all other record
description entries of that file.
For EXTERNAL files, all file description entries in the run unit that are
associated with the EXTERNAL file must specify the same data description
entry for data-name-2 with the same relative location within the
associated record.
X The requirement for identical data description entries is not enforced,
X but the key must have the same relative location in the records, as well
X as the same length.
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