Add missing unique indexes from #7234

db/migrate/20170813164435_add_missing_unique_indexes.rb

+class AddMissingUniqueIndexes < ActiveRecord::Migration[5.1]
+  def up
+    cleanup
+
+    remove_index :aspect_visibilities, name: :shareable_and_aspect_id
+    add_index :aspect_visibilities, %i[shareable_id shareable_type aspect_id],
+              name: :index_aspect_visibilities_on_shareable_and_aspect_id,
+              length: {shareable_type: 189}, unique: true
+
+    add_index :blocks, %i[user_id person_id], name: :index_blocks_on_user_id_and_person_id, unique: true
+
+    add_index :roles, %i[person_id name], name: :index_roles_on_person_id_and_name, length: {name: 190}, unique: true
+  end
+
+  def down
+    remove_index :aspect_visibilities, name: :index_aspect_visibilities_on_shareable_and_aspect_id
+    add_index :aspect_visibilities, %i[shareable_id shareable_type aspect_id], name: :shareable_and_aspect_id,
+              length: {shareable_type: 189}, unique: true
+
+    remove_index :blocks, name: :index_blocks_on_user_id_and_person_id
+
+    remove_index :roles, name: :index_roles_on_person_id_and_name
+  end
+
+  def cleanup
+    aspect_visibilities_where = "WHERE a1.shareable_id = a2.shareable_id AND a1.shareable_type = a2.shareable_type " \
+                                "AND a1.aspect_id = a2.aspect_id AND a1.id > a2.id"
+    blocks_where = "WHERE b1.user_id = b2.user_id AND b1.person_id = b2.person_id AND b1.id > b2.id"
+    roles_where = "WHERE r1.person_id = r2.person_id AND r1.name = r2.name AND r1.id > r2.id"
+
+    if AppConfig.postgres?
+      execute "DELETE FROM aspect_visibilities AS a1 USING aspect_visibilities AS a2 #{aspect_visibilities_where}"
+      execute "DELETE FROM blocks AS b1 USING blocks AS b2 #{blocks_where}"
+      execute "DELETE FROM roles AS r1 USING roles AS r2 #{roles_where}"
+    else
+      execute "DELETE a1 FROM aspect_visibilities a1, aspect_visibilities a2 #{aspect_visibilities_where}"
+      execute "DELETE b1 FROM blocks b1, blocks b2 #{blocks_where}"
+      execute "DELETE r1 FROM roles r1, roles r2 #{roles_where}"
+    end
+  end
+end