Data domain

A data domain defines the type of data value that is held by an attribute in a data model. IBM Industry Models are delivered with predefined data domains.

Properties

Name (mandatory)

A textual name that identifies this data domain.

e.g. String
e.g. Percentage

Description (mandatory)

A complete and unambiguous description of this data domain.

Owning package (mandatory)

The owning package to which this model element belongs. All domains are owned by the Data Domain package, which is in a separate data domain model that is delivered with the IBM Industry Models.

e.g. package Data Domain owns atomic domain String
e.g. package Data Domain owns atomic domain Percentage

Specific atomic domain properties

Atomic domains define the type of data value that is held by an attribute in a data model such as string or number. Predefined atomic domains are used in the logical models. The Atomic Warehouse Model (AWM), for example, uses data domains to ensure a consistent approach in the use of data types for attributes that have a similar purpose in the logical model.

Figure 1. Examples of an atomic domain in Standards - Data Domain model

Each atomic data domain has the following characteristics:

Name: A textual name that identifies this data domain.
Description: A complete and unambiguous description of this data domain.

Base type (mandatory)

A base type on which this data domain is defined.

e.g. DECIMAL
e.g. VARCHAR
e.g. DATE

Length, precision, scale

Precise information regarding the length, the precision or the scale of a base type. Each base type has its required characteristics (for example, length for a VARCHAR, precision and scale for a DECIMAL and none for a DATE).