While I'm looking into the possibilities provided by the other posters, these tips don't require more advanced knowledge than I have ;-).

Thank you for warning me about the anonymous array overhead. Will change that immediately.

Furthermore, I'm on little endian, so the string comparison should work just fine. However, I don't want to sort on the remainder of the string as it is now. Will run a test first, and post the results here.

Thanks a lot,

Jeroen
"We are not alone"(FZ)

Update: Must have made some difference in memory usage, but it's still way too much. Made a rough calculation of the memory usage with system monitor (gnome) and this little script: 

#!/usr/bin/perl

my $size=1E6;
my $f = 2;
print "Increasing memory print each step by a factor $f\n\n";
while(1){
  print "\tCreating array of $size items...Press enter to continue....
+";
  my $b = <STDIN>;
  my @a=1..$size;
  print "...done. Press enter to continue.";
  $b = <STDIN>;
  chomp $b;
  $b=~ /[qxQX]/ and exit;
  $size *= $f;
}

[download]
It's about 44 megabytes for every million items in an array. No way my 12 M records are going to fit in physical memory. I'm back to Radixsort and alike.

In reply to Re: Re: Sorting data that don't fit in memory by jeroenes
in thread Sorting data that don't fit in memory by jeroenes

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.