4.2.16 "COBOL Language Reference" IBM Library Server

4.2.16 RERUN Clause

X >_Workstation_> Under AIX, OS/2, and Windows, the RERUN clause is not
X supported for line sequential files or for programs compiled with the
X THREAD compiler option. If you use NOTHREAD, the RERUN clause is treated
X as a comment. <_Workstation_<

The RERUN clause specifies that checkpoint records are to be taken. Subject to the restrictions given with each phrase, more than one RERUN clause can be specified.

For information regarding the checkpoint data set definition and the checkpoint method required for complete compliance to the COBOL 85 Standard, see IBM COBOL for OS/390 & VM Programming Guide.

Do not use the RERUN clause:

On files with the EXTERNAL attribute
X In programs with the RECURSIVE attribute
X In programs compiled with the THREAD option (Workstation only)
X In methods

file-name-1

Must be a sequentially organized file.

assignment-name-1

The external data set for the checkpoint file. It must not be the same assignment-name as that specified in any ASSIGN clause throughout the entire program, including contained and containing programs. For QSAM files, it has the format:


        ___ Format--QSAM File ______________________________________________ 
       |                                                                    |
       | >>__ _________ __ _____ __name__________________________________>< |
       |     |_label- _|  |_S- _|                                           |
       |                                                                    |
       |____________________________________________________________________|

That is, it must be a QSAM file. It must reside on a tape or direct access device. See also Appendix E, "ASCII Considerations for OS/390 and VM" in topic APPENDIX1.5.

VSAM and QSAM Considerations:

The file named in the RERUN clause must be a file defined in the same program as the I-O-CONTROL paragraph, even if the file is defined as GLOBAL.

X SORT/MERGE Considerations:

X When the RERUN clause is specified in the I-O-CONTROL paragraph,
X checkpoint records are written at logical intervals determined by the
X sort/merge program during execution of each SORT or MERGE statement in
X the program. When it is omitted, checkpoint records are not written.

X There can be only one SORT/MERGE I-O-CONTROL paragraph in a program,
X and it cannot be specified in contained programs. It will have a
X global effect on all SORT and MERGE statements in the program unit.

EVERY integer-1 RECORDS

A checkpoint record is to be written for every integer-1 record in file-name-1 that is processed.

When multiple integer-1 RECORDS phrases are specified, no two of them can specify the same file-name-1.

If you specify the integer-1 RECORDS phrase, you must specify assignment-name-1.

EVERY END OF REEL/UNIT

A checkpoint record is to be written whenever end-of-volume for file-name-1 occurs. The terms REEL and UNIT are interchangeable.

Note: This clause is not supported. If you code it in your program, it will be treated as a comment.

When multiple END OF REEL/UNIT phrases are specified, no two of them can specify the same file-name-1.

The END OF REEL/UNIT phrase can only be used if file-name-1 is a sequentially organized file.

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4.2.16 RERUN Clause

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