加索引

db/migrate/20160907061917_add_index_to_course_contributor_scores.rb

@@ -0,0 +1,7 @@
+class AddIndexToCourseContributorScores < ActiveRecord::Migration
+  def change
+    add_index :course_contributor_scores, [:course_id, :user_id]
+    add_index :members, :course_id
+    add_index :course_groups, :course_id
+  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 => 20160907055119) do
+ActiveRecord::Schema.define(:version => 20160907061917) do
 
   create_table "activities", :force => true do |t|
     t.integer  "act_id",                                  :null => false
@@ -517,6 +517,8 @@ ActiveRecord::Schema.define(:version => 20160907055119) do
     t.integer  "news_num",             :default => 0
   end
 
+  add_index "course_contributor_scores", ["course_id", "user_id"], :name => "index_course_contributor_scores_on_course_id_and_user_id"
+
   create_table "course_groups", :force => true do |t|
     t.string   "name"
     t.integer  "course_id"
@@ -524,6 +526,8 @@ ActiveRecord::Schema.define(:version => 20160907055119) do
     t.datetime "updated_at", :null => false
   end
 
+  add_index "course_groups", ["course_id"], :name => "index_course_groups_on_course_id"
+
   create_table "course_infos", :force => true do |t|
     t.integer  "course_id"
     t.integer  "user_id"
@@ -1140,6 +1144,7 @@ ActiveRecord::Schema.define(:version => 20160907055119) do
     t.integer  "is_collect",        :default => 1
   end
 
+  add_index "members", ["course_id"], :name => "index_members_on_course_id"
   add_index "members", ["project_id"], :name => "index_members_on_project_id"
   add_index "members", ["user_id", "project_id", "course_id"], :name => "index_members_on_user_id_and_project_id", :unique => true
   add_index "members", ["user_id"], :name => "index_members_on_user_id"