Repository: rails/rails
File: activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb (Ruby)

Code before:
      # Passing a hash containing +:from+ and +:to+ will make this change
      # reversible in migration:
      #
      #   change_table_comment(:posts, from: "old_comment", to: "new_comment")
      def change_table_comment(table_name, comment_or_changes)
        raise NotImplementedError, "#{self.class} does not support changing table comments"
      end

      # Changes the comment for a column or removes it if +nil+.
      #
      # Passing a hash containing +:from+ and +:to+ will make this change
      # reversible in migration:
      #
      #   change_column_comment(:posts, :state, from: "old_comment", to: "new_comment")
      def change_column_comment(table_name, column_name, comment_or_changes)
        raise NotImplementedError, "#{self.class} does not support changing column comments"
      end

      # Enables an index to be used by queries.
      #
      #   enable_index(:users, :email)
      def enable_index(table_name, index_name)
        raise NotImplementedError, "#{self.class} does not support enabling indexes"
      end

      # Disables an index not to be used by queries.
      #
      #   disable_index(:users, :email)
      def disable_index(table_name, index_name)
        raise NotImplementedError, "#{self.class} does not support disabling indexes"
      end

      def create_schema_dumper(options) # :nodoc:
        SchemaDumper.create(self, options)
      end

      def use_foreign_keys?
        supports_foreign_keys? && foreign_keys_enabled?
      end

      # Returns an instance of SchemaCreation, which can be used to visit a schema definition
      # object and return DDL.
      def schema_creation # :nodoc:
        SchemaCreation.new(self)
      end

      def bulk_change_table(table_name, operations) # :nodoc:
        sql_fragments = []
        non_combinable_operations = []

        operations.each do |command, args|

Review comment (suggestion):
The double negative here is throwing me off, what do you think about either of these instead?
```suggestion
      # Prevents an index from being used by queries.
```

or

```suggestion
      # Disables an index for use by queries.
```

Code after:
      # Passing a hash containing +:from+ and +:to+ will make this change
      # reversible in migration:
      #
      #   change_table_comment(:posts, from: "old_comment", to: "new_comment")
      def change_table_comment(table_name, comment_or_changes)
        raise NotImplementedError, "#{self.class} does not support changing table comments"
      end

      # Changes the comment for a column or removes it if +nil+.
      #
      # Passing a hash containing +:from+ and +:to+ will make this change
      # reversible in migration:
      #
      #   change_column_comment(:posts, :state, from: "old_comment", to: "new_comment")
      def change_column_comment(table_name, column_name, comment_or_changes)
        raise NotImplementedError, "#{self.class} does not support changing column comments"
      end

      # Enables an index to be used by queries.
      #
      #   enable_index(:users, :email)
      def enable_index(table_name, index_name)
        raise NotImplementedError, "#{self.class} does not support enabling indexes"
      end

      # Prevents an index from being used by queries.
      #
      #   disable_index(:users, :email)
      def disable_index(table_name, index_name)
        raise NotImplementedError, "#{self.class} does not support disabling indexes"
      end

      def create_schema_dumper(options) # :nodoc:
        SchemaDumper.create(self, options)
      end

      def use_foreign_keys?
        supports_foreign_keys? && foreign_keys_enabled?
      end

      # Returns an instance of SchemaCreation, which can be used to visit a schema definition
      # object and return DDL.
      def schema_creation # :nodoc:
        SchemaCreation.new(self)
      end

      def bulk_change_table(table_name, operations) # :nodoc:
        sql_fragments = []
        non_combinable_operations = []

        operations.each do |command, args|