destroy_model_storage (DataMapper::Migrations::OracleAdapter)

    # File lib/dm-core/migrations.rb, line 933
          def destroy_model_storage(model, forced = false)
            table_name = model.storage_name(name)
            truncate_or_delete = self.class.auto_migrate_with
            if storage_exists?(table_name)
              if truncate_or_delete && !forced
                statement = case truncate_or_delete
                when :truncate
                  truncate_table_statement(model)
                when :delete
                  delete_table_statement(model)
                else
                  raise ArgumentError, "Unsupported auto_migrate_with option"
                end
                execute(statement)
                @truncated_tables ||= {}
                @truncated_tables[table_name] = true
              else
                execute(drop_table_statement(model))
                @truncated_tables[table_name] = nil if @truncated_tables
              end
            end
            # added destroy of sequences
            reset_sequences = self.class.auto_migrate_reset_sequences
            table_is_truncated = @truncated_tables && @truncated_tables[table_name]
            unless truncate_or_delete && !reset_sequences && !forced
              if sequence_exists?(model_sequence_name(model))
                if table_is_truncated && !forced
                  statement = reset_sequence_statement(model)
                else
                  statement = drop_sequence_statement(model)
                end
                execute(statement) if statement
              end
            end
            true
          end