QueryTracer

• https://github.com/daemon/query_tracer

DESCRIPTION

QueryTracer is designed to log where from queries to DB were made.

Origins

Original code was built for Scribd by Dmitry Shteflyuk.

TODO

Rewrite SQL queries adding small trace as a comment. It will show where long running queries came from.

Usage

Add following code to config/initializers/query_tracer.rb:

QueryTracer.configure do |tracer|
  tracer.enabled = true
  tracer.colorize = true
  tracer.show_revision = true
  tracer.multiline = true
  tracer.exclude_sql << %r{FROM sqlite_master}
end

QueryTracer::Logger.attach_to :active_record

exclude_queries will contain default expressions list for currently selected DB.

To set up tracer.colorize according to value of config.colorize_logging in your environment settings (config/development.rb) you could write

tracer.colorize = ActiveSupport::LogSubscriber.colorize_logging

Example

Let's say we have model

class User < ActiveRecord::Base
  scope :active, where(:active => true)

  def self.traceme
    active.to_a
  end
end

Invoking User.traceme will produce in logs:

  SQL (0.9ms)   SELECT name
 FROM sqlite_master
 WHERE type = 'table' AND NOT name = 'sqlite_sequence'

  User Load (25.8ms)  SELECT "users".* FROM "users" WHERE "users"."active" = 't'
^^^^ Called from: Rev[d11816c90c2a38dcd866b115ed2ffa28d7d84e2c]
-> /Users/dm/Projects/tmp/loggertest/app/models/user.rb:5:in `traceme'
-> (irb):1:in `irb_binding'