Using appropriate data types can improve performance when you query and access data. To assign appropriate data types, open ...

Using appropriate data types can improve performance when you query and access data. To assign appropriate data types, open the table in Design view and change the data type of the field to the data type the wizard suggests above. Caution: Changing a data type will erase existing data that doesn't match the new data type and will limit the kind of information you can store in the field.