Quick bucketing of PG logs

bucket.rb

#!/usr/bin/env ruby

module Enumerable 
  #  sum of an array of numbers
  def sum
    return self.inject(0){|acc,i|acc +i}
  end
 
  #  average of an array of numbers
  def average
    return self.sum/self.length.to_f
  end

  def sample_variance
    avg=self.average
    sum=self.inject(0){|acc,i|acc +(i-avg)**2}
    return(1/self.length.to_f*sum)
  end
 
  #  standard deviation of an array of numbers
  def standard_deviation
    return Math.sqrt(self.sample_variance)
  end
end

outputs = {}
STDIN.each_line do |line|
  data = line.gsub(';', '').split(' ')
  outputs[data[1].to_i] = [] unless outputs[data[1].to_i]
  outputs[data[1].to_i] << data[0].to_f
end

outputs.keys.sort.each do |k|
  v = outputs[k]
  puts k
  puts "  Min: #{v.min}"
  puts "  Avg: #{v.average}"
  puts "  Max: #{v.max}"
  puts "  SDV: #{v.standard_deviation}
end

command

cat pglog_oldskool | grep "SELECT \* " | cut -d " " -f 7,30 | ./bucket.rb

DS ID Mod 10

cosm@dbfun1:~$ cat pglog_dsidmod | grep "SELECT * " | cut -d " " -f 7,30 | ./bucket.rb
1
Min: 6.513
Avg: 610.452147472204
Max: 3522.191
SDV: 693.578756776515
3
Min: 6.299
Avg: 476.082501403585
Max: 2003.337
SDV: 492.663970770051
7
Min: 6.316
Avg: 1080.75604513889
Max: 2990.404
SDV: 808.373659920346
10
Min: 6.446
Avg: 181.532417197452
Max: 554.524
SDV: 119.950128016387