Here's my thoughts.

Save all information needed to generate the report, and get a md5 of this information to use as a filename. Store a copy of the dataset in this file, possible with DBD::SQLite.

Now, you probably do not want to be making your report queries with your main apache process. It would probably be a good idea to have a seperate server process that gets you the actual data, to avoid having an expensive and huge apache process spin it's wheels while the query runs to return some piddly amount of computationally intensive data.

This would also be handy for paging through datasets, because once the dataset is created you can page within it without re-running the query, as long as no filter options change.

Update:

OK, so yeah I cheated - I know the problem ;) I still think this method mixed in with some interstitial goodness will take care of it though.

In reply to Re: (OT) Handling long-running queries with mod_perl/Mason by Tuppence
in thread (OT) Handling long-running queries with mod_perl/Mason by Ovid

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.