Actually, if you are doing sequential processing, zEDC is perhaps the
best as it "write"s full-tracks, regardless of the BLKSIZE
specified. With zEDC, the BLKSIZE is just the size of data passed
to/from the application and no longer the physical data "written" to disk.
Michael
At 12:14 PM 11/23/2022, Mike Schwab wrote:
If you are doing sequential reads and writes, half track is the best
you can do. If you are random reading small records, I.E. 80 byte,
400 bytes, 2000 bytes; then smaller blocks lead to less I/O per
record, since you aren't using most of the data read, and the larger
the block the less you use. VSAM use a 4K physical record unless
you specify a very large CI size.
On Wed, Nov 23, 2022 at 11:56 AM Paul Gorlinsky <p...@atsmigrations.com> wrote:
>
> Short block more efficient? Elaborate please. Space utilization
and efficient are not necessarily the same. Latency issues vary a
lot depending on the exact box being used for DASD. DS6K v DS8K.
DS8K with rotating v solid-state ...
>
> QSAM v BPAM v BSAM v etc...
>
> General guidelines ...
>
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--
Mike A Schwab, Springfield IL USA
Where do Forest Rangers go to get away from it all?
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