DECIMAL data type

The DECIMAL data type is a decimal number with precision total digits and with scale digits after the decimal point.

Syntax

DECIMAL [ ( precision [ , scale ] ) ]

Parameters

precision An integer expression between 1 and 127, inclusive, that specifies the number of digits in the expression. The default setting is 30.
scale An integer expression between 0 and 127, inclusive, that specifies the number of digits after the decimal point. The scale value should always be less than, or equal to, the precision value. The default setting is 6.
The defaults can be changed by setting database options. For information, see precision option and scale option.

Remarks

The DECIMAL data type is an exact numeric data type; its accuracy is preserved to the least significant digit after arithmetic operations.

The storage required for a decimal number can be estimated as

2 + int( (before + 1)/2 ) + int( (after + 1)/2 )

The function int takes the integer portion of its argument, and before and after are the number of significant digits before and after the decimal point. The storage is based on the value being stored, not on the maximum precision and scale allowed in the column.

DECIMAL can also be specified as DEC. Regardless of which syntax is used, the data type is described as DECIMAL.

If you are using a precision of 20 or less and a scale of 0, it may be possible to use one of the integer data types (BIGINT, INTEGER, SMALLINT, or TINYINT) instead. Integer values require less storage space than NUMERIC and DECIMAL values with a similar number of significant digits. Operations on integer values, such as fetching or inserting, and arithmetic operators, typically perform better than operations on NUMERIC and DECIMAL values.

DECIMAL is semantically equivalent to NUMERIC.

Note

If you create a column or variable of a DECIMAL data type with a precision or scale that exceeds the precision and scale settings for the database, values are truncated to the database settings. So, if you notice truncated values in a column or variable defined as DECIMAL, check that precision and scale do not exceed the database option settings. See precision option and scale option.

Standards and compatibility

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