query_call_stack.rb

module Profiling
  class CallStackTracker
    cattr_accessor :query_call_stacks do
      []
    end
    IGNORED_SQL = [/^PRAGMA (?!(table_info))/, /^SELECT currval/, /^SELECT CAST/, /^SELECT @@IDENTITY/, /^SELECT @@ROWCOUNT/, /^SAVEPOINT/, /^ROLLBACK TO SAVEPOINT/, /^RELEASE SAVEPOINT/, /^SHOW max_identifier_length/]
    def call(name, start, finish, message_id, values)
      # FIXME: this seems bad. we should probably have a better way to indicate
      # the query was cached
      unless 'CACHE' == values[:name]
        self.class.query_call_stacks << caller unless IGNORED_SQL.any? { |r| values[:sql] =~ r }
      end
    end
  end
  def self.query_call_stacks(&block)
    ActiveRecord::QueryCounter.query_call_stacks = []
    yield
    ActiveRecord::QueryCounter.query_call_stacks
  end
end

ActiveSupport::Notifications.subscribe('sql.active_record', Profiling::CallStackTracker.new)