remove unnecessary count query for post_versions listing

config/initializers/query_trace.rb

@@ -0,0 +1,84 @@
+# yields a stacktrace for each SQL query
+# put this file in config/initializers
+class QueryTrace < ActiveSupport::LogSubscriber
+  include Term::ANSIColor
+  attr_accessor :trace_queries
+
+  def sql(event)  #:nodoc:
+    return unless QueryTrace.enabled? && logger.debug? && Rails.env.development?
+    stack = Rails.backtrace_cleaner.clean(caller)
+    first_line = stack.shift
+    return unless first_line
+
+    msg = prefix + bold + cyan + "#{first_line}\n" + reset
+    msg += cyan + stack.join("\n") + reset
+    debug msg
+  end
+
+  # :call-seq:
+  # Klass.enabled?
+  #
+  # yields boolean if SQL queries should be logged or not
+
+  def self.enabled?
+    defined?(@trace_queries) && @trace_queries
+  end
+
+  # :call-seq:
+  # Klass.status
+  #
+  # yields text if QueryTrace has been enabled or not
+
+  def self.status
+    QueryTrace.enabled? ? 'enabled' : 'disabled'
+  end
+
+  # :call-seq:
+  # Klass.enable!
+  #
+  # turn on SQL query origin logging
+
+  def self.enable!
+    @trace_queries = true
+  end
+
+  # :call-seq:
+  # Klass.disable!
+  #
+  # turn off SQL query origin logging
+
+  def self.disable!
+    @trace_queries = false
+  end
+
+  # :call-seq:
+  # Klass.toggle!
+  #
+  # Toggles query tracing yielding a boolean indicating the new state of query
+  # origin tracing
+
+  def self.toggle!
+    enabled? ? disable! : enable!
+    enabled?
+  end
+
+protected
+
+  def prefix  #:nodoc:
+    bold(magenta('Called from: ')) + reset
+  end
+end
+
+QueryTrace.attach_to :active_record
+
+trap('QUIT') do
+  # Sending 2 backspace characters removes the ^\ that is 
+  # printed to the console.
+  rm_noise = "\b\b"
+
+  QueryTrace.toggle!
+  puts "#{rm_noise}=> QueryTrace #{QueryTrace.status}"
+end
+
+QueryTrace.enable! if ENV['QUERY_TRACE']
+puts "=> QueryTrace #{QueryTrace.status}; CTRL-\\ to toggle"