We support standard IEEE 754 floating point types.

double is a 64-bit standard FP value. Accepted synonyms are float8 and float64.

float is a 32-bit standard FP value. Accepted synonyms are float4, and float32.

Floating point values include special values, such as NaN (not a number), -Infinity, and -Infinity. An alternative spelling for -Infinity is -inf, and an alternative spelling for Infinity is inf, and an alternative spelling for 'NaN' is 'nan'. When written as SQL literals, these values have to be surrounded by simple quotes: 'inf'. Please note that these strings are case-sensitive and spaces are ignored.

Infinity plus any finite value equals Infinity, as does Infinity plus Infinity. Infinity minus Infinity yields NaN.

NaN (not a number) value is used to represent undefined results. An operation with a NaN input yields NaN. The only exception is when the operation's output does not depend on the NaN value: an example is NaN raised to the zero power yields one.

In sorting order NaN is considered greater than all other values.

The legal operations are + (plus, unary and binary), - (minus, unary and binary), * (multiplication), / (division). (modulus).

Division or modulus by zero return NaN.

Casting a string to a floating-point value will produce the value 0 when parsing fails.

Casting a value that is out of the supported range to a floating point type will produce a value that is inf or -inf.

Please note that numeric values with a decimal point have the decimal type by default. To write a floating-point literal you have to include the e for exponent using the following grammar:

digits.digits[e[+-]digits]

[digits].digits[e[+-]digits]

Alternatively, you can use an explicit cast:

REAL '1.23'  -- string style
1.23::REAL   -- PostgreSQL style