After some search, I found elegant solution from Aaron, but still not able to meet my requirement. 

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

my $key = shift;
my @cols = @ARGV;
my %h;

die "Usage: grp.pl id_column field1 [field2]...\n" unless @cols;
# $ARGV[0] is the Base column
# $ARGV[1..x] is the list of columns to add up

while(<DATA>){
  chomp;
  my @f = split;
  for (@cols){
    $h{$f[$key]}{$_}{t} += $f[$_];
    $h{$f[$key]}{$_}{n}++;
  }
}

for my $k (sort keys %h){
  print $k;
  print "\t$h{$k}{$_}{n}\t$h{$k}{$_}{t}" for @cols;
  print "\n";
}

__DATA__
server01: 2015-06-01T12:40:03-04:00  DB101                  10 MB/sec
server01: 2015-06-01T12:40:03-04:00  DB202                   5 MB/sec
server01: 2015-06-01T12:40:03-04:00  ASM                     2 MB/sec
server01: 2015-06-01T12:40:03-04:00  MYDB101                 2 MB/sec
server01: 2015-06-01T12:40:03-04:00  MYDB202                 5 MB/sec
server01: 2015-06-01T12:40:03-04:00  _OTHER_DB_             30 MB/sec
server01: 2015-06-01T12:41:03-04:00  DB101                   3 MB/sec
server01: 2015-06-01T12:41:03-04:00  DB202                   4 MB/sec
server01: 2015-06-01T12:41:03-04:00  ASM                     2 MB/sec
server01: 2015-06-01T12:41:03-04:00  MYDB101                 9 MB/sec
server01: 2015-06-01T12:41:03-04:00  MYDB202                 7 MB/sec
server01: 2015-06-01T12:41:03-04:00  _OTHER_DB_             50 MB/sec
server02: 2015-06-01T12:40:03-04:00  DB101                  90 MB/sec
server02: 2015-06-01T12:40:03-04:00  DB202                   9 MB/sec
server02: 2015-06-01T12:40:03-04:00  ASM                     2 MB/sec
server02: 2015-06-01T12:40:03-04:00  MYDB101                 3 MB/sec
server02: 2015-06-01T12:40:03-04:00  MYDB202                 1 MB/sec
server02: 2015-06-01T12:40:03-04:00  _OTHER_DB_             90 MB/sec
server02: 2015-06-01T12:41:03-04:00  DB101                   1 MB/sec
server02: 2015-06-01T12:41:03-04:00  DB202                   4 MB/sec
server02: 2015-06-01T12:41:03-04:00  ASM                     2 MB/sec
server02: 2015-06-01T12:41:03-04:00  MYDB101                 7 MB/sec
server02: 2015-06-01T12:41:03-04:00  MYDB202                 7 MB/sec
server02: 2015-06-01T12:41:03-04:00  _OTHER_DB_             55 MB/sec

[download]
Got below result:
./grp.pl 2 3
ASM     4       8
DB101   4       104
DB202   4       22
MYDB101 4       21
MYDB202 4       20
_OTHER_DB_      4       225

[download]

Could you please help in finding a way to group on time column based on Hour and print as per my requirement.

Sample of Required output: 

Frequency Minute:
           collectionTime DB101 DB202 ASM MYDB101 MYDB202 _OTHER_DB_
2015-06-01T12:40:03-04:00   100    14   4       5       6        140  
2015-06-01T12:41:03-04:00     4     8   4      16      14        105

[download]
Frequency Hour:
           collectionTime DB101 DB202 ASM MYDB101 MYDB202 _OTHER_DB_
2015-06-01T12:00:00-04:00     
2015-06-01T13:00:00-04:00

[download]

In reply to Re^2: Computing results through Arrays by yasser8@gmail.com
in thread Computing results through Arrays by yasser8@gmail.com

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