RE: ovrdbf SHARE parameter

As to why a CLP would use SHARE(*YES) without OPNQRYF, there are two
common reasons I've encountered:

a) To improve performance. If you go many years back, when computers
had only kilobytes of memory, the cost (in terms of memory and
performance) of opening a file multiple times was very high. So if you
had multiple programs using the same file, you'd share the ODP so
they'd
all share the same file open, improving performance and reducing memory
footprint. IMHO, this is not a good practice today.

b) There was a common misconception that OVRDBF SHARE(*YES) in CL was
the equivalent of the // FILEDISP-SHR in OCL. People translating their
OCL's to CL's when converting from the S/36 would commonly replace
//FILE NAME-FOO,DISP-SHR to OVRDBF FILE(FOO) SHARE(*YES).

I haven't seen it in years, but I used to see reports (especially error
reports) tied together through this method. If OVRPRTF errorprint
SHARE(*YES) is issued before the first program opens ERRORPRINT, then the
resultant output of all programs that open ERRORPRINT within that job will
be interspersed.

Note that I didn't comment on whether I considered it good practice.

Dennis Lovelady
http://www.linkedin.com/in/dennislovelady
--
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nondiscrimination."
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