FLOAT

CockroachDB supports various inexact, floating-point number with up to 17 digits of decimal precision.

They are handled internally using the standard double-precision (64-bit binary-encoded) IEEE754 format.

Names and Aliases

Name	Aliases
FLOAT	None
REAL	FLOAT4
DOUBLE PRECISION	FLOAT8

Syntax

A constant value of type FLOAT can be entered as a . For example: 1.414 or -1234.

The special IEEE754 values for positive infinity, negative infinity and NaN (Not-a-Number) cannot be entered using numeric literals directly and must be converted using an or an from a string literal instead.

The following values are recognized:

Syntax	Value
inf, infinity, +inf, +infinity	+∞
-inf, -infinity	-∞
nan	NaN (Not-a-Number)

For example:

• FLOAT '+Inf'
• '-Inf'::FLOAT
• CAST('NaN' AS FLOAT)

Size

A FLOAT column supports values up to 8 bytes in width, but the total storage size is likely to be larger due to CockroachDB metadata.

Examples

> CREATE TABLE floats (a FLOAT PRIMARY KEY, b REAL, c DOUBLE PRECISION);

> SHOW COLUMNS FROM floats;

  column_name | data_type | is_nullable | column_default | generation_expression |  indices  | is_hidden
--------------+-----------+-------------+----------------+-----------------------+-----------+------------
  a           | FLOAT8    |    false    | NULL           |                       | {primary} |   false
  b           | FLOAT4    |    true     | NULL           |                       | {primary} |   false
  c           | FLOAT8    |    true     | NULL           |                       | {primary} |   false
(3 rows)

> INSERT INTO floats VALUES (1.012345678901, 2.01234567890123456789, CAST('+Inf' AS FLOAT));

> SELECT * FROM floats;

+----------------+--------------------+------+
|       a        |         b          |  c   |
+----------------+--------------------+------+
| 1.012345678901 | 2.0123456789012346 | +Inf |
+----------------+--------------------+------+
(1 row)
# Note that the value in "b" has been limited to 17 digits.

Supported casting and conversion

FLOAT values can be to any of the following data types:

Type	Details
INT	Truncates decimal precision and requires values to be between -2^63 and 2^63-1
DECIMAL	Causes an error to be reported if the value is NaN or +/- Inf.
BOOL	0 converts to false; all other values convert to true
STRING	—

See also