Thanks a lot Aaron Sir !!!! I tried coding the way you said but not sure where I am going wrong, getting lot of errors "Use of uninitialized value in string". I tried debugging but in vain. Also no idea how to print the keys in a single line, I am not able to meet this requirement "print them as headers, formatted to fit what's coming below" Please do not mind for these silly mistakes, I am still beginner in perl. 

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

my %h;
my %m;
my %db;

while(<DATA>){
  chomp;
  my @fields = split;
  my ($date,$database_name,$speed) = @fields[1,2,3];
  my ($date_hour,$minute) = split /:/, $date ;
  my $date_hour_minute = join (':',$date_hour,$minute) ;
  
  $h{$date_hour}{$database_name} += $speed;
  $m{$date_hour_minute}{$database_name} += $speed;
  $db{$database_name} = 1;
}

for my $db_keys (sort keys %db){
    print "$db_keys";
    for my $h_keys (sort keys %h){
        print $h_keys;
            for my $db_keys (sort keys %db){
                print "$h{$h_keys}{$db_keys}";
                print "\n";
            }
    }
}

[download]

Will be thankful to you if you could help me please...

In reply to Re^4: Computing results through Arrays by yasser8@gmail.com
in thread Computing results through Arrays by yasser8@gmail.com

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