Storing NUMBER Data - Teradata Database

Storing NUMBER Data

You can achieve optimal space savings for NUMBER data using either multivalue compression, algorithmic compression, or a combination of both.

NUMBER data is stored as a variable length field from 0 to 18 bytes in width. You can use the NUMBER type to represent both fixed point and floating point decimal numbers, depending on the syntax you use to specify the type. In the following table, the characters p and s represent precision and scale, respectively.

General Type	Syntax	Functional Description
Fixed point	NUMBER(p,s)	Similar to DECIMAL(p,s)
	NUMBER(p)	Similar to DECIMAL(p)
Floating point	NUMBER(*,s)	Floating point decimal with s fractional digits
	NUMBER	A floating point number
	NUMBER(*)	Same as NUMBER

The following table highlights the approximate equivalences/valid substitutions between the fixed and floating point NUMBER types with other exact (fixed point) and approximate (floating point) types.

You can use this NUMBER type …	Anywhere you can use this data type …	With a maximum precision of this many digits …
Fixed point	DECIMAL NUMERIC	38
Floating point	FLOAT REAL DOUBLE PRECISION	40

Whether a NUMBER type is used to represent a fixed point value or a floating point value, it is stored in the same way and with the same accuracy. See “Floating Point NUMBER Types” on page 729, “Non‑INTEGER Numeric Data Types” on page 731, and SQL Data Types and Literals for more information about the NUMBER type.