Dimensions and Units 

As noted in the tables above, MDM has a compound data type for storing physical measurements that combines a numeric value with a unit of measure. It allows you to associate a physical dimension with a measurement field or numeric attribute, and then to assign to every numeric value a unit of measure chosen from the list of units applicable to that dimension.

MDM currently has built-in support for over 70 different physical dimensions and over 750 different units of measure. In addition, MDM is able to convert between different units, for proper comparison and sorting of numeric values with different units within a list, impossible with most other systems that often store numeric values and units of measure as a single text string or in two distinct fields.

Physical dimensions make it easy to enforce data integrity, since units of measure must be selected from a predefined list of units rather than typed in by the user as a text string.

Measurement fields and numeric attributes are 4-byte real fields with the exception of the dimensions Time and Frequency, which require the additional precision of 8-byte real fields.