add index to migration

db/migrate/20200204084723_create_cities.rb

@@ -6,5 +6,6 @@ class CreateCities < ActiveRecord::Migration[6.0]
       t.string :city_description
       t.timestamps
     end
+    add_index :cities, :city_name
   end
 end

db/migrate/20200204084729_create_companies.rb

@@ -10,5 +10,6 @@ class CreateCompanies < ActiveRecord::Migration[6.0]
       t.string :size
       t.timestamps
     end
+    add_index :companies, :email
   end
 end

db/schema.rb

@@ -32,6 +32,7 @@ ActiveRecord::Schema.define(version: 2020_02_04_084755) do
     t.string "city_description"
     t.datetime "created_at", precision: 6, null: false
     t.datetime "updated_at", precision: 6, null: false
+    t.index ["city_name"], name: "index_cities_on_city_name"
   end
 
   create_table "companies", options: "ENGINE=InnoDB DEFAULT CHARSET=utf8", force: :cascade do |t|
@@ -44,6 +45,7 @@ ActiveRecord::Schema.define(version: 2020_02_04_084755) do
     t.string "size"
     t.datetime "created_at", precision: 6, null: false
     t.datetime "updated_at", precision: 6, null: false
+    t.index ["email"], name: "index_companies_on_email"
   end
 
   create_table "industries", options: "ENGINE=InnoDB DEFAULT CHARSET=utf8", force: :cascade do |t|