Maximum records that a ps file can support



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Maximum records that a ps file can support

Postby sid_sep28 » Mon Jun 10, 2013 7:13 pm

Hi All,
I have a need in my project where the data volume may be as high as 25 million. Please advise if this can be supported by a PS file or do i need to convert it to a tape file. If PS file will work please specify what are the things i need to keep in mind?
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Re: Maximum records that a ps file can support

 

Re: Maximum records that a ps file can support

Postby enrico-sorichetti » Mon Jun 10, 2013 7:29 pm

I have a need in my project where the data volume may be as high as 25 million.

25 millions of what ???
if the 25 millions are bytes that would be 24 megabytes which would mean around 30 cylinders
if the 25 millions are records, then it would depend on the record length
( 1 track contains a bit less of 56 KB )

Please advise if this can be supported by a PS file or do i need to convert it to a tape file.

PS is the acronym for Physical Sequential organization
A PS file can reside indifferently on DASD or TAPE
cheers
enrico
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Re: Maximum records that a ps file can support

Postby dick scherrer » Mon Jun 10, 2013 8:04 pm

Hello and welcome to the forum,

Determine the size of your output data and talk with your storage management people to learn how to properly allocate this output file on your system.
Hope this helps,
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Re: Maximum records that a ps file can support

Postby Robert Sample » Mon Jun 10, 2013 9:02 pm

As noted, your question is VERY poorly worded.

For 80-byte records, the approximate limit (up until z/OS allowed more than 65,535 tracks per volume) is just under 2.7 BILLION records; the updated z/OS allows over 10 BILLION 80-byte records per data set on DASD.

However, actual limits -- as also noted -- are established by your site policies and you should consult your site support group for assistance.
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Re: Maximum records that a ps file can support

Postby steve-myers » Mon Jun 10, 2013 11:02 pm

To expand on Mr. Sample's comments; there are two limits
  • Volume capacity. Until some time in the 1990s, no direct access storage device marketed by IBM had as many as 65535 tracks. This is no longer true, though many 3390 volumes are defined as smaller.
  • Data set size. Until z/OS V1R7, the maximum data set size on a single volume was limited to 65535 tracks. This limit still applies to regular PDS data sets, but not to sequential data sets, though allocating a larger data set may be difficult and you must discuss this with your storage management support. Your program may, though this is unlikely, have problems supporting a large sequential data set. We cannot help you.
Of course, regardless of data set or volume size constraints, a sequential disk data set can extend to multiple volumes. The precise rules for this are site specific, and you must discuss this with your storage management support.

As others have indicated, unless your record size is quite large, I do not think there are any major issues with 25 million records.
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