my $docID=0;
my $tf=0;
my $index=0;
my $Aa=time();
for(1 .. 2000000)
{
   $docID = vec ($dp, $index++, 32);
   $tf = vec ($dp, $index++, 32); $ TERM FREQUENCY
                    
    $vec{$docID}=$tf;  ### SAve Data 
    for(1 .. $tf)
    {
    my $poss=vec ($dp, $index++, 32);
    $pos{$docID}{$poss}=\$order;# save Data
    }    
}
print "unpack vector in \t",time()-$Aa,"  secs...\n";
[download]

Get a faster computer. On my notebook (about 1 year old, 2 GHz CPU and enough RAM) this takes about 1.6 seconds. I don't say that boast, but rather to tell you that your hardware isn't up to date.

And are you sure that you actually access all items of that data structure? Right now you just build it up, but don't use it, so there's no way for us to tell.

It may run that fast because the OP didn't supply a value for $dp. I pasted the code into a file that has use strict at the top, and it blew up immediately.

Assuming that $pos and $poss are two different things, and $pos is defined somewhere outside of the code snippet, you can save a bundle by doing something like this:

my $docpos = $pos{$docID};
for (1 .. $tf) {
  $docpos->{vec ($dp, $index++, 32)}=\$order;
}
[download]

It may seem trivial, but that's about 2000000*avg_tf dereferences.
Getting rid of an unnecessary "my" variable should also pick up a few extra cycles.

I'd like a sample value for $dp. A Data::Dumper representation of it or some code to cook up a reasonable facsimile would work. When I run this on my computer, it doesn't do anything interesting until I give it a value for that, but what particular value it has could have a big effect on performance.

Thanks.

Here is the whole code...I should give it earlier



use strict;
use Devel::Size qw(size);


my $df=500000;my $tf=3;
my $wektor = '';
my $packed = '';
my $nr=0;
for(0 .. $df)
{
   vec ($wektor, $nr++, 32) = $_; # DOC ID......
   vec ($wektor, $nr++, 32) = $tf;  # TF......
   for(0 .. $tf)
   {
        vec ($wektor, $nr++, 32) = $_+10;  # POSITIONS
   }
}
print "Vector's size: " .
  size( $wektor ) . " bytes\n";



###################### UNPACK VECTOR2.....
my %vec;my %pos;
my $docID=0;
my $tf=0;
my $index=0;
my $order=1;
my $Aa=time();
for(0 .. $df)
{
        $docID = vec ($wektor, $index++, 32);
        $tf = vec ($wektor, $index++, 32);
        $vec{$docID}=$tf;
#        print "Doc id: $docID\ttf: $tf\n";
        for(0 .. $tf)
        {
            my $last=vec ($wektor, $index++, 32);
                        $pos{$docID}{$last}=$order;
        }    
}
print "unpack vector in \t",time()-$Aa,"  secs..\n";
[download]