Remove index for users.current sign in at

changelogs/unreleased/remove_index_for_users-current_sign_in_at.yml

+---
+title: Remove index for users.current sign in at
+merge_request: 10401
+author: blackst0ne

db/migrate/20170402231018_remove_index_for_users_current_sign_in_at.rb

+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class RemoveIndexForUsersCurrentSignInAt < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  # Set this constant to true if this migration requires downtime.
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    if index_exists? :users, :current_sign_in_at
+      if Gitlab::Database.postgresql?
+        execute 'DROP INDEX CONCURRENTLY index_users_on_current_sign_in_at;'
+      else
+        remove_index :users, :current_sign_in_at
+      end
+    end
+  end
+
+  def down
+    add_concurrent_index :users, :current_sign_in_at
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20170329124448) do
+ActiveRecord::Schema.define(version: 20170402231018) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -1252,7 +1252,6 @@ ActiveRecord::Schema.define(version: 20170329124448) do
   add_index "users", ["authentication_token"], name: "index_users_on_authentication_token", unique: true, using: :btree
   add_index "users", ["confirmation_token"], name: "index_users_on_confirmation_token", unique: true, using: :btree
   add_index "users", ["created_at"], name: "index_users_on_created_at", using: :btree
-  add_index "users", ["current_sign_in_at"], name: "index_users_on_current_sign_in_at", using: :btree
   add_index "users", ["email"], name: "index_users_on_email", unique: true, using: :btree
   add_index "users", ["email"], name: "index_users_on_email_trigram", using: :gin, opclasses: {"email"=>"gin_trgm_ops"}
   add_index "users", ["ghost"], name: "index_users_on_ghost", using: :btree