marshal_dump

# File activerecord/lib/active_record/connection_adapters/schema_cache.rb, line 76
      def marshal_dump
        # if we get current version during initialization, it happens stack over flow.
        @version = ActiveRecord::Migrator.current_version
        [@version] + [@columns, @columns_hash, @primary_keys, @tables].map { |val|
          Hash[val]
        }
      end