Pointless issue of the day. This has bothered me for 20 years. I figured its
about time I ask, why? Why does an "empty" KSDS (a KSDS that has never been
"loaded") have what seems to be to be a "special" behavior, one that is
different than a KSDS that had records but no longer has any (all records have
been deleted).
For example, if a file in this "never loaded" state is opened for input by
IDCAMS you get this:
PRINT INFILE(CCMIGR)
IDC3300I ERROR OPENING DVFJS.CCARD.CCMIGRX
IDC3351I ** VSAM OPEN RETURN CODE IS 160
IDC0005I NUMBER OF RECORDS PROCESSED WAS 0
where
160
The operands specified in the ACB or GENCB macro are
inconsistent with each other or with the information in the
catalog record. This error can also occur when the VSAM
cluster being opened is empty.
If opened by SORT (DFSORT)
IEC161I
072-053,DEFVSAM,PRINT1,CCMIGR,,,DVFJS.CCARD.CCMIGRX,DVFJS.CCARD.CCMIGRX.DATA,CATALOG.USERCAT.PPCAT
where
IEC161I (072)
Specific information for this return code: The data set was empty, but the
ACB (access method control block) for the data set indicated that it was being
opened for input only.
System action
OPEN processing ends for the data set. The error flag (ACBERFLG) in the ACB
(access method block) for the data set is set to 160 (X'A0').
When opened by a COBOL program, you get file status 35 (An OPEN statement with
the INPUT, I-O, or EXTEND phrase was attempted on a non-optional file that was
unavailable.), unless you declare it as OPTIONAL, in which case you get file
status 05 (An OPEN statement was successfully executed, but the referenced
optional file was unavailable at the time the OPEN statement was executed. The
file had been created if the open mode was I-O or EXTEND.)
Is this "feature" supposed to be helpful in some obscure edge case? Or is it
simply always annoying?
The OPTIONAL solution in COBOL is generally how we get around this issue,
rather than loading a dummy record or something. But why? Why, why, why does
this behavior even exist?
Frank
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