---------------------------<snip>------------------------------
255? Really?
Bob
-------------------------<snip>-------------------------
The PDS directory records are a fixed size, LRECL=255, I believe. My
reason to allocate a PDS filling a track, or multiples, with the
directory comes from thinking half-track blocking is efficient for
reads and if I use one half, or full track directory then I am doing
the least amount of I/O as possible. Reality may be different. The
optimum number of PDS entries to allocate depends on the type of PDS,
loadlib or other. For other, are statistics kept or not. How many of
us ignore taking the time to plan the need and just allocate with a
larger number than we need? I chose to allocate larger based on
number of tracks. I no longer use a PDS for non-loadlib datasets.
--------------------------<unsnip>-----------------------
Ken, the physical BLKSIZE of the directory is 255, plus a 8-byte
physical key. You can set a PDS BLKSIZE to any value you like, but it
will have NO effect on the directory characteristics. On a 3390, that
means that you will always get 45 directory blocks to a track, or 44
blocks plus the EOF mark.
-------------------------<unsnip>--------------------------------
OOOOOOOOOPS!!!
Wide mouth and large feet!
Bob, you are correct to question. I should have said 256! I completely
forgot that the length byte at record start isn't included in the length
that it indicates.
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