Logical Data Modeling - Attribute

An attribute is a property or characteristic of a primary element (entity, relationship)

The values for each attribute are defined in terms of properties.

An attribute is known as a:

• field in object
• variable in pure code
• column metadata - in a relational model
• variable metadata - in statistic

The value of an attribute may have one of this functionalities:

• Logical Data Modeling - Classifier (Label, Class, Tag) - Descriptif Attribute
• Dimensional Data Modeling - Measure
• Logical Data Modeling - Global Identifier (Fully Qualified Name, Canonical Form)

Each attribute are defined in terms of properties (metadata attributes):

• Name:
  • It provides a semantic meaning for the values.
  • the name of the attribute may contain a prefix of its element
• Description
• Attribute Source Category:
  • Basic,
  • Derived,
  • Designed
• Data type (what class of data can be stored in that attribute)
• Length and/or precision
• Domain: enumeration, range of permitted, legal values / Format patterns (what values an attribute can legitimately take on)
• Default value or algorithm (what default value are recorded if not specified by the user)
• Optionality: Mandatory or optional
• Density / Sparsity
• analytical property - descriptive or measure

An Attribute Value that cannot be deduced or calculated. Examples:

• Student name
• Birthday

See Logical Data Modeling - (Derived|Calculated) Attribute (Derived Data)

The Attribute is created to overcome the system constraints. The value of a Designed Attribute does not change. Attribute does not change.

Examples:

• Student ID,
• Course number.