eah -- HARBA and HURBA (High Allocated Relative Byte Address and High
> Used RBA) live in the catalog entry.
>
Would this have any adverse interaction with writing a physical
EOF at the beginning of a newly allocated extent?
Actually it is in the VVR in the VVDS. Writing an EOF would have no
purpose since VSAM does not use EOFs. The RBA values tell it where the
end of data is so VSAM never reads beyond them.
Unlike non-VSAM, VSAM has a "file open" flag so if the file is not
closed properly, the next OPEN does an implicit VERIFY function, which
reads the data and determines where the real HURBA is.
An EOF In VSAM beyond the HURBA would probably be ignored, even on a
VERIFY, but it serves no purpose.
Why the restriction to SAM? Allocation ought to
write EOF whenever a NEW primary extent is allocated, regardless
of known or unknown DSORG.
As Doug Henry pointed out in his quotes from the manuals (thanks, Doug,
I knew it had to be somewhere), SMS datasets write the EOF for DSORG=PS
AND unspecified DSORG, so it covers all dataset types where the EOF may
be important.
--
Bruce A. Black
Senior Software Developer for FDR
Innovation Data Processing 973-890-7300
personal: [EMAIL PROTECTED]
sales info: [EMAIL PROTECTED]
tech support: [EMAIL PROTECTED]
web: www.innovationdp.fdr.com
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