动态表添加索引

db/migrate/20160324074942_add_index_to_forge_activities.rb

@@ -1,5 +1,5 @@
 class AddIndexToForgeActivities < ActiveRecord::Migration
   def change
-    add_index :forge_activities, [:project_id, :forge_act_id, :created_at]
+    add_index :forge_activities, [:project_id, :forge_act_id, :created_at, :forge_act_type], :name => "forge_act_index"
   end
 end

db/migrate/20160325030146_add_index_to_course_actiivities.rb

@@ -0,0 +1,5 @@
+class AddIndexToCourseActiivities < ActiveRecord::Migration
+  def change
+    add_index :course_activities, [:course_id, :course_act_id, :course_act_type, :created_at], :name => "course_act_index"
+  end
+end

db/migrate/20160325030423_add_index_to_user_activities.rb

@@ -0,0 +1,5 @@
+class AddIndexToUserActivities < ActiveRecord::Migration
+  def change
+    add_index :user_activities, [:act_id, :act_type, :container_id, :created_at], :name => "user_act_index"
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
 
-ActiveRecord::Schema.define(:version => 20160324052634) do
+ActiveRecord::Schema.define(:version => 20160325030423) do
 
   create_table "activities", :force => true do |t|
     t.integer  "act_id",                                  :null => false
@@ -405,6 +405,8 @@ ActiveRecord::Schema.define(:version => 20160324052634) do
     t.datetime "updated_at",      :null => false
   end
 
+  add_index "course_activities", ["course_id", "course_act_id", "course_act_type", "created_at"], :name => "course_act_index"
+
   create_table "course_attachments", :force => true do |t|
     t.string   "filename"
     t.string   "disk_filename"
@@ -731,6 +733,7 @@ ActiveRecord::Schema.define(:version => 20160324052634) do
   end
 
   add_index "forge_activities", ["forge_act_id"], :name => "index_forge_activities_on_forge_act_id"
+  add_index "forge_activities", ["project_id", "forge_act_id", "created_at", "forge_act_type"], :name => "forge_act_index"
 
   create_table "forge_messages", :force => true do |t|
     t.integer  "user_id"
@@ -1812,6 +1815,8 @@ ActiveRecord::Schema.define(:version => 20160324052634) do
     t.integer  "user_id"
   end
 
+  add_index "user_activities", ["act_id", "act_type", "container_id", "created_at"], :name => "user_act_index"
+
   create_table "user_extensions", :force => true do |t|
     t.integer  "user_id",                            :null => false
     t.date     "birthday"