New `user_stats` table to keep track of queried information on a user.

This is information that is not usually needed when representing a user
and is in a separate table with a has one relationship to avoid querying
it all the time.

app/models/user.rb

@@ -35,6 +35,7 @@ class User < ActiveRecord::Base
   has_one :github_user_info, dependent: :destroy
   has_one :cas_user_info, dependent: :destroy
   has_one :oauth2_user_info, dependent: :destroy
+  has_one :user_stat, dependent: :destroy
   belongs_to :approved_by, class_name: 'User'
 
   has_many :group_users, dependent: :destroy
@@ -60,6 +61,7 @@ class User < ActiveRecord::Base
   after_save :update_tracked_topics
 
   after_create :create_email_token
+  after_create :create_user_stat
 
   before_destroy do
     # These tables don't have primary keys, so destroying them with activerecord is tricky:
@@ -538,6 +540,12 @@ class User < ActiveRecord::Base
     end
   end
 
+  def create_user_stat
+    stat = UserStat.new
+    stat.user_id = self.id
+    stat.save!
+  end
+
   def create_email_token
     email_tokens.create(email: email)
   end

app/models/user_stat.rb

@@ -0,0 +1,5 @@
+class UserStat < ActiveRecord::Base
+
+  belongs_to :user
+
+end

db/migrate/20130911182437_create_user_stats.rb

@@ -0,0 +1,15 @@
+class CreateUserStats < ActiveRecord::Migration
+  def up
+    create_table :user_stats, :id => false do |t|
+      t.references :user, null: false
+      t.boolean :has_custom_avatar, default: false, null: false
+    end
+    execute "ALTER TABLE user_stats ADD PRIMARY KEY (user_id)"
+    execute "INSERT INTO user_stats (user_id) SELECT id FROM users"
+  end
+
+  def down
+    drop_table :user_stats
+  end
+
+end

spec/models/user_stat_spec.rb

@@ -0,0 +1,12 @@
+require 'spec_helper'
+
+describe UserStat do
+
+  it { should belong_to :user }
+
+  it "is created automatically when a user is created" do
+    user = Fabricate(:evil_trout)
+    user.user_stat.should be_present
+  end
+
+end