On 11/28/2014 12:20 PM, Sam Golob wrote:
Hi Folks,
I was just involved in an exercise to improve an old file
copying program from CBT Tape File 316. It is called FFYCOPY,
and it was written in the mid-1970's by Frank Yates (courtesy of
Jim Marshall). This program's "copy engine" uses BSAM with double
buffers, and for its time, it was very fast, since BSAM (using
the READ and WRITE macros) deals with copying blocks of data
instead of records. Of course, QSAM (using the GET and PUT
macros) is geared to copying records.
<SNIPPAGE>
You didn't mention it, but, if you will look at the NCPs, you
could have as many as 255 I/Os outstanding. As I recall, you will
have to use CHECK for this type of processing.
The NCP value can be coded in JCL, or it can be inserted into the
DCB and be a system controlled value. In using this, you can, as
I recall, even handle striped data sets much faster.
Just my 2 cents worth -- which may not be worth anything at all.
Regards,
Steve Thompson
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