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  • 1.  db2 zos max tablespace size

    Posted Apr 20, 2022 03:26 AM
    Hello.

    I'm building a presentation and after some research, this what I got (for DB2 z/os v12):

    1. Simple and segmented - 64GB.
    2.classic (non-uts) partitioned - 16TB.
    3.PBG & PBR - 128TB.
    4.PBR RPN - 4PB

    Please correct me if I'm wrong.

    Thanks,
    Shay.

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    ShayMillerMataf
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  • 2.  RE: db2 zos max tablespace size

    Posted 11 days ago
    Can anyone help please?

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    ShayMillerMataf
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  • 3.  RE: db2 zos max tablespace size

    Posted 11 days ago
    Hi!

    Simple and Segmented: Yep 2GB * 32 Linear Datasets gives you 64GB

    Classic (non-uts) partitioned - 16TB. - It varies all over the place depending on how many parts you had/have and/or with LARGE or not. Real mess! Basically without LARGE it was 64GB with LARGE it was 16TB. It also varied between releases. V7 was a lot less the V8 for example (better to gloss over these objects as they are all deprecated these days anyway!!)

    PBG & PBR - 128TB. Yep - DSSIZE is here which means you are in the Matrix of PGSIZE/DSSIZE which in Db2 10 got to 256GB DSSIZE with 32K Pagesize and 512 Parts which gives 128TB as max size.

    PBR RPN - 4PB . Yep - Each partition can be 1024GB and with 4096 parts you get 4PB.


    Index sizes also varied all over the place... NPI piece count? Max size of a PI ? Great fun working those things out!!!


    Roy Boxwell

    SOFTWARE ENGINEERING GmbH and SEGUS Inc.
    -Product Development-



    Vagedesstrasse 19
    40479 Dusseldorf/Germany
    Tel. +49 (0)211 96149-675
    Fax +49 (0)211 96149-32
    Email: R.Boxwell@seg.de
    Web http://www.seg.de
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    Amtsgericht Düsseldorf, HRB 37894
    Geschäftsführung: Gerhard Schubert, Ulf Heinrich




  • 4.  RE: db2 zos max tablespace size

    Posted 10 days ago
    Shay,

    The limit for partitioned (non-uts) tablespaces is the same as for UTS PBG and PBR with absolute page numbering, and for partitioned indexes: 128TB for 32K page size, with DSSIZE of 32G or larger.

    This was the limit even before the introduction of UTS - as per my copy of the V8 SQL Reference.

    Neil









  • 5.  RE: db2 zos max tablespace size

    Posted 9 days ago
    Thanks Dan &Neil.

    Neil, can you please say where it states the the limit is 128TB in the mnaual please?
    From what in know, it's 16 TB  (confimred also by Dan).

    Thanks,
    Shay.


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    ShayMillerMataf
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  • 6.  RE: db2 zos max tablespace size

    Posted 8 days ago
    Shay,

    Unfortunately the current documentation is at best ambiguous, but the limit that existed in V8 certainly won't have been reduced, will it? If you happen to have a V8 SQL manual, or can find one online, then you could see it for yourself.

    The Db2 11 documentation is still available online for the time being, and it certainly doesn't rule out applicability of the 128TB limit to "classic" partitioned table spaces.

    A change made to the doc for the Db2 12 CREATE TABLESPACE statement to exclude UTS PBR with relative page numbering has succeeded in implying that it doesn't apply, but that can't be true.

    The page "Limits in Db2 for z/OS" however still implies that such a tablespace can have a DSSIZE up to 256GB and can have 512 partitions of that size.








  • 7.  RE: db2 zos max tablespace size

    Posted 8 days ago
    (Sent prematurely by accident!)

    In V8 the maximum DSSIZE was 64GB, but you can have 2048 partitions of that size or 4096 of 32GB, either of which gives 128TB, if you use 32K page size.

    A tablespace defined as LARGE is indeed limited to 16TB, as Roy (not Dan) says, but that's an obsolete specification and it can't achieve the current maximum possible size.

    Regards 
    Neil

    PS Dan didn't post in this thread but Roy did.






  • 8.  RE: db2 zos max tablespace size

    Posted 8 days ago
    Yeah, as I said in my post - Forget these objects - Too confusing to explain all the different limits and they are *all* deprecated in Db2 12 FL504 anyways...

    Roy Boxwell

    SOFTWARE ENGINEERING GmbH and SEGUS Inc.
    -Product Development-



    Vagedesstrasse 19
    40479 Dusseldorf/Germany
    Tel. +49 (0)211 96149-675
    Fax +49 (0)211 96149-32
    Email: R.Boxwell@seg.de
    Web http://www.seg.de
    Link zur Datenschutzerklärung

    Software Engineering GmbH
    Amtsgericht Düsseldorf, HRB 37894
    Geschäftsführung: Gerhard Schubert, Ulf Heinrich