if you're running updates in batches don't forget about quickish stuff that might work.

perl -le 'for(1..30_000_000){$x=int(rand(30_000_000));print $x;}' >/tm
+p/randnums

time sort -n /tmp/randnums > /tmp/randnumssorted

real    2m0.819s
user    1m52.631s
sys     0m2.798s

# used about 200m memory

time uniq -c /tmp/randnumssorted > /tmp/randuniq

real    0m11.225s
user    0m8.520s
sys     0m1.019s

time sort -rn /tmp/randuniq >/tmp/randuniqsort

real    1m0.062s
user    0m41.569s
sys     0m3.125s

head /tmp/randuniqsort 
     10 7197909
     10 6080002
     10 2718836
     10 21596579
      9 8257184
      9 8116236
      9 7721800
      9 7706211
      9 7657721
      9 7490738

[download]

pull out your account numbers, sort/uniq to find duplicates. takes about 3 minutes and 200m memory.

there's nothing wrong with going over the file twice if it makes it easier to process.

In reply to Re: Bloom::Filter Usage by Anonymous Monk
in thread Bloom::Filter Usage by jreades

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.