Page 1 of 1

Recommendation for optimal BLKSIZE

PostPosted: Thu 24 Aug 2017, 18:36
by axdmlm
I have a PDSE I use to hold assembly listings.
I allocated it with BLSKIZE=13300.
Shoulld I change it?

Thanks

Re: Recommendation for optimal BLKSIZE

PostPosted: Thu 24 Aug 2017, 18:55
by steve-myers
Not worth the effort. Remember PDSE maps PDS data records over 4K records.

Re: Recommendation for optimal BLKSIZE

PostPosted: Thu 24 Aug 2017, 22:11
by axdmlm
Just wanted to be sure.
Thanks.

Re: Recommendation for optimal BLKSIZE

PostPosted: Thu 24 Aug 2017, 23:02
by steve-myers
On second thought, use SDB. This will allocate BLKSIZE=32718. It won't make any difference in data set size or EXCPs, but it will reduce - a little - your CPU time as there will be fewer interactions between the program and PDSE.

HLASM supports RECFM=VBA or VBM. This will mean a larger BLKSIZE , and the data set will have fewer bytes because of trailing blank elimination, so there will be fewer interactions between your program and PDSE.

Re: Recommendation for optimal BLKSIZE

PostPosted: Fri 25 Aug 2017, 17:09
by steve-myers
As for your

IEC141I 013-EC,IGG0191A,AXDMLMJ,L,SYSPRINT,0A77,FUSR27,AXDMLM.LINKLIST(PGM1)

I think the Binder wants RECFM=FBA,LRECL=121. It won't do LRECL=133.

See http://publibz.boulder.ibm.com/cgi-bin/ ... 0709091949