ADD index for project_type column in projects table

db/migrate/20201020083709_add_index_to_projects.rb

@@ -0,0 +1,5 @@
+class AddIndexToProjects < ActiveRecord::Migration[5.2]
+  def change
+    add_index :projects, :identifier, name: 'index_projects_on_identifier'
+  end
+end