PID TTY      STAT   TIME  MAJFL   TRS   DRS  RSS %MEM COMMAND
22842 pts/1    R+     0:00      0    10  6941 1680  0.1 perl xxx.pl
create all the hashes
  PID TTY      STAT   TIME  MAJFL   TRS   DRS  RSS %MEM COMMAND
22842 pts/1    S+     0:23      2    10 932137 883884 85.5 perl xxx.pl
clean out hashes
  PID TTY      STAT   TIME  MAJFL   TRS   DRS  RSS %MEM COMMAND
22842 pts/1    R+     0:30     31    10 932137 885632 85.6 perl xxx.pl
we're done

##</code><code>##

#!/usr/bin/perl
use strict;use warnings;

sub showtime {
    print `ps -p $$ v`;
    }

showtime;
print "create all the hashes\n";
my %h1;
foreach my $one (0..64000) {
   $h1{$one}={};
   foreach my $two (0..2) {
      $h1{$one}{$two}='foo';
      }
   }

my %h2;
foreach my $one (0..2200000) {
   $h2{$one}={};
   foreach my $two (0..3) {
      $h2{$one}{$two}='foo';
      }
   }
my %h3;
foreach my $one (0..1) {
   $h3{$one}={};
   foreach my $two (0..1) {
      $h3{$one}{$two}={};
      foreach my $three (0..1) {
         $h3{$one}{$two}{$three}={};
         foreach my $four (0..9) {
            $h3{$one}{$two}{$three}{$four}={};
            foreach my $five (0..14) {
               $h3{$one}{$two}{$three}{$four}{$five}={};
               foreach my $six (0..39) {
                  $h3{$one}{$two}{$three}{$four}{$five}{$six}='bar';
                  }
               }
            }
         }
      }
   }


showtime;
print "clean out hashes\n";
%h1= ();
%h2= ();
%h3= ();
showtime;
print "we're done\n";