A 43 million element array of 20-ish character strings should come in well below 4GB.
On a 64-bit system with a modern perl, it uses about 3.5Gb, assuming that the strings and the array were created in the most efficient way possible. Based on the OPs comments, I would guess they aren't being generated in the most efficient way possible; and together with the overhead of whatever the rest of code does, that swap really is an issue.

In that case, it may be worth the OP's while to try an initial sequential read of the the array to get all the elements swapped backed in, before hitting random elements. Whether this will increase performance is pure speculation at this point.

Another possibility is to use a single large string, divided into blocks of 20 chars, to avoid the overhead of the array and SVs; then access individual elements using substr().

Dave.

In reply to Re^2: Very Large Arrays by dave_the_m
in thread Very Large Arrays by Desade

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.