services/api/db/migrate/20181213183234_add_expression_index_to_links.rb

   1 class AddExpressionIndexToLinks < ActiveRecord::Migration
   2   def up
   3     ActiveRecord::Base.connection.execute 'CREATE INDEX index_links_on_substring_head_uuid on links (substring(head_uuid, 7, 5))'
   4     ActiveRecord::Base.connection.execute 'CREATE INDEX index_links_on_substring_tail_uuid on links (substring(tail_uuid, 7, 5))'
   5   end
   6
   7   def down
   8     ActiveRecord::Base.connection.execute 'DROP INDEX index_links_on_substring_head_uuid'
   9     ActiveRecord::Base.connection.execute 'DROP INDEX index_links_on_substring_tail_uuid'
  10   end
  11 end