perl Generate CDF for Benchmark Tests

use Cwd;
use DBI;
use Benchmark;

use Time::HiRes qw(usleep ualarm gettimeofday tv_interval);
use POSIX;

$count=10000;
@nums = (0 .. 9999);

print "wj Test of  execute selects of 100 items\n";
$loop_time=new Benchmark;

for ($i=1 ; $i <= $count ; $i++)
{
  my ($key_value)=$random[$i];
  my ($query)= "select * from bench1 where id<$key_value and id>($key_value+100)";  
  print "$query\n" if ($opt_debug);
$t0 = [gettimeofday]; 
  $sth = $dbh->prepare($query);
  while ($sth->fetchrow_arrayref) { };      
$nums[$i-1] = floor(tv_interval($t0, [gettimeofday])*1000000 + 0.5);

  $sth->finish;
};
$end_time=new Benchmark;

print "Time for prepared_select ($count): " .
    timestr(timediff($end_time, $loop_time),"all") . "\n";


#wj
@nums = sort{$a<=>$b}(@nums);
open (MYFILE, '>tmp');
for ($i= 0; $i< $count; $i++) {
 $percent = $i/$count;
 $cdf = join "",$nums[$i],"\t",$percent; 
 if ($nums[$i] !=  $nums[$i+1] || $i == count-1) {
  print MYFILE "$cdf\n"; 
 }
}
close (MYFILE);