The ANSI/ISO SQL:2011 standard defines two families of predefined numeric data types.
- Exact
- Approximate
An exact predefined numeric data type is one that can represent a value exactly. Exact numeric types are divided between the true integer types, which specify a precision but not a scale, and the fractional types, which can specify both a precision and a scale.
Teradata also supports forms of the NUMBER data type, which can be used to represent both exact numeric values and floating point numeric values, depending on the syntax used to define the value. By the definitions the ANSI/ISO SQL:2011 standard uses for exact and approximate predefined numeric data types, the NUMBER data type as implemented by Teradata is neither an exact nor an approximate numeric type.