tracking down which lines of code are executing mysql queries

queries.rb

$queries = 0
$locations = Hash.new { |h, k| h[k] = 0 }

class ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter
  def execute_with_tracking(sql, name = nil)
    $queries += 1
    caller.select{ |c| c =~ /app/ }.each{ |c| $locations[c] += 1 }
    execute_without_tracking(sql, name)
  end

  alias_method_chain :execute, :tracking
end

#
# code you want to profile here
#

$locations.sort_by{|l| l[1]}.reverse[0, 20].each do |location, count|
  puts "#{count}:\t#{location}"
end; 1

puts "#{$queries} queries"