Hi,

Situation is the folloowing : Memory is low and data is large. What I need is an algorithm to locate repetitive enteries with a prespecified cutoff (let say 5 repeats) in a file that containes 70000000 string enteries (file example: 

ent1  up to 100 characters..
ent2  up to 100 characters..
ent3  up to 100 characters..
ent2  up to 100 characters..
ent7  up to 100 characters..
ent3  up to 100 characters..
ent5  up to 100 characters..
ent5  up to 100 characters..
ent2  up to 100 characters..
..

[download]
) I only have app. 500MB of RAM at my disposal (other things are running and I cannot afford to SWAP). Does anyone has a suggestion ?

b

PS Don't care if it is slow as long as it can be processed within 6 hours.

In reply to [SOLVED]finding repetitions by baxy77bax

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.