Informix

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  • 1.  Pages allocated / pages used

    Posted Fri August 26, 2022 08:45 AM
    Hi Fellas,

    we have a RHEL8 system with 14.10.FC7WE running.
    4K dbspace with a huge wide table with 182 columns and ~10 million rows.

    Number of pages allocated 16777215
    Number of pages used 16777215

    Problem is, that we already reducded that table from ~28m to 10m now and again we see that issue with pages.

    Informix is not releasing the pages when we do a delete?


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    Marc Demhartner
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    #Informix


  • 2.  RE: Pages allocated / pages used

    IBM Champion
    Posted Fri August 26, 2022 10:33 AM

    Hi Marc,

    You need to repack and shrink after deleting.

    Regards,
    David.

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    David Williams
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    Original Message


  • 3.  RE: Pages allocated / pages used

    Posted Mon August 29, 2022 10:12 AM
    Could you give me an example how to do so ?

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    Marc Demhartner
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    Original Message


  • 4.  RE: Pages allocated / pages used

    Posted Wed August 31, 2022 06:23 AM
    Hi Marc.

    David probably means this:

    EXECUTE FUNCTION sysadmin:task('table repack shrink', 'table-name');

    That could take a long time. If you can tolerate the table being locked and have room for a copy, the quickest method is:

    ALTER TABLE table-name TYPE (RAW);
    ALTER FRAGMENT ON TABLE table-name INIT IN same-dbspace;
    ALTER TABLE table-name TYPE (STANDARD);

    That may refuse if there are referential constraints, and you should ideally take a level 0 archive afterwards.

    If the table contains variable length columns, consider setting this before the rebuild.

    onmode -wf MAX_FILL_DATA_PAGES=1

    Regards,
    Doug

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    Doug Lawry
    Oninit Consulting
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    Original Message