Numbers

The numeric data types are categorized as exact numerics: binary integer and decimal; decimal floating point; and approximate numerics: floating-point

Binary integer includes small integer, large integer, and big integer. Binary numbers are exact representations of integers. Decimal numbers are exact representations of real numbers. Binary and decimal numbers are considered exact numeric types. Decimal floating point numbers include DECFLOAT(16) and DECFLOAT(34), which are capable of representing either 16 or 34 significant digits. Floating-point includes single precision and double precision. Floating-point numbers are approximations of real numbers and are considered approximate numeric types.

All numbers have a sign, a precision, and a scale. If a column value is zero, the sign is positive. Decimal floating point has distinct values for a number and the same number with various exponents (for example: 0.0, 0.00, 0.0E5, 1.0, 1.00, 1.0000). The precision is the total number of binary or decimal digits excluding the sign. The scale is the total number of binary or decimal digits to the right of the decimal point. If there is no decimal point, the scale is zero.

Small integer (SMALLINT)
A small integer is a binary integer with a precision of 15 bits. The range of small integers is -32768 to +32767.
Large integer (INTEGER)
A large integer is a binary integer with a precision of 31 bits.
Big integer (BIGINT)
A big integer is a binary integer with a precision of 63 bits.
Single precision floating-point (REAL)
A single precision floating-point number is a short (32 bits) floating-point number.
Double precision floating-point (DOUBLE or FLOAT)
A double precision floating-point number is a long (64 bits) floating-point number.
Decimal (DECIMAL or NUMERIC)
A decimal number is a packed decimal number with an implicit decimal point.
Decimal floating-point (DECFLOAT)
A decimal floating-point value is an IEEE 754r number with a decimal point. The position of the decimal point is stored in each decimal floating-point value.
Numeric host variables
Numeric host variables can be defined in all languages with a few exceptions.
String representations of numeric values
String representations of numeric values can be used in some contexts. A valid string representation of a numeric value must conform to the rules for numeric constants.
Subnormal numbers and underflow
The decimal floating-point data type has a set of non-zero numbers that fall outside the range of normal decimal floating-point values. These numbers are called subnormal.

Parent topic: Data types