COBOL Manual for TNS/E Programs (H06.03+)

Environment Division
HP COBOL Manual for TNS/E Programs—520347-003
6-25
FILE-CONTROL Paragraph
Each such file has an INSERTIONORDER attribute that governs this behavior for all its
alternate keys. An insertion-ordered alternate key cannot share an alternate key file
with other keys of different lengths, or with other alternate keys that are not insertion
ordered. The attribute can be changed only by using either a call to the operating
system routine SET or by use of the File Utility Program (FUP), not by any COBOL
language phrase or clause. In FUP, the BUILDKEYRECORDS and LOADALTFILE
commands do not support loading of insertion-ordered alternate key records.
There are size and performance penalties for using insertion-ordered duplicate
alternate keys; the size of the alternate file increases and the access time increases as
the number of records having duplicate alternate keys increases. For more information
see the File Utility Program (FUP) Reference Manual or the Guardian Procedure Calls
Reference Manual.
The data description of each altkey, its relative location within the file record, and the
specification of the DUPLICATES attribute must correlate with one of the alternate
record keys defined when the file was created. The file-control entry can contain at
most one ALTERNATE RECORD KEY clause that describes a particular alternate
record key of the file. If an alternate record key is not referenced in the source program
Procedure Division, then it is not necessary to describe it in the file-control entry. A
maximum of 31 alternate record keys can be described for a single file.
No altkey can reference an item whose leftmost character position within the file
record corresponds to the leftmost character position of the item referenced by any
other altkey associated with this file.
File-Control Entries for Sequential Files
HP COBOL supports two types of sequential disk files:
•
A disk file created as a sequential file (also called an entry-sequenced file on
NonStop systems)
•
An unstructured disk file
Also, a COBOL file defined as sequential can be assigned to a tape file, to a device
such as a terminal or process, or to $RECEIVE. See OPEN and RECEIVE-CONTROL
Paragraph.