EXPLORING DECIMAL AND NUMERIC DATA TYPES

Numeric and decimal data types are treated the same by SQL Server. Both
data types have precision and scale properties. The precision property
defines the length of the numeric value. The scale identifies how many of
the precision's digits will be to the right of the decimal point. The
amount of bytes used to store the decimal data type depends on the precision
property. The following shows the number of bytes, based on the precision
property of the numeric data type:


* Precision between 1 and 9 will use 5 bytes.

* Precision between 10 and 19 will use 9 bytes.

* Precision between 20 and 28 will use 13 bytes.

* Precision between 29 and 38 will use 17 bytes.


A precision of 28 is the maximum for SQL Server version 7.0 (SS70); a
precision of 38 is the maximum for SQL Server 2000 (SS2K). If precision is
not used to define the decimal data type, the default value is 18 for
versions SS70 and SS2K.

When the decimal data type is set up with a precision of 10 and a scale
of 0, it has a length in bytes of 9. In contrast, the integer data type,
with a precision of 10 and scale of 0, has a length in bytes of 4. If you
use a decimal data type with precision of 10 and scale of 0 to hold
integer values, it will take up more space in the database than the integer
data type. (Note: All data types can hold negative, as well as positive,
values.)

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