Understanding Dimension Attributes

A dimension attribute is an OLAP Catalog metadata entity. This means that it is a logical object, identified by name and owner, within the OLAP Catalog.

Dimension attributes define sets of level attributes for a dimension. Dimension attributes may include level attributes for some or all of the dimension's levels. For time dimensions, the dimension attributes end date and time span must be defined for all levels.

Use the procedures in the CWM2_OLAP_DIMENSION_ATTRIBUTE package to create, drop, and lock dimension attributes and to specify descriptive information for display purposes.

Several dimension attribute names are reserved, because they have special significance within CWM2. The level attributes comprising a reserved dimension attribute will be mapped to columns containing specific information. The reserved dimension attributes are listed in Table 12-1.

Table 12-1 Reserved Dimension Attributes

Dimension Attribute	Description
`Long Description`	A long description of the dimension member.
`Short Description`	A short description of the dimension member.
`End Date`	For a time dimension, the last date in a time period. (Required)
`Time Span`	For a time dimension, the number of days in a time period. (Required)
`Prior Period`	For a time dimension, the time period before this time period.
`Year Ago Period`	For a time dimension, the period a year before this time period.
`ET Key`	For an embedded total dimension, the embedded total key, which identifies the dimension member. (Required)
`Parent ET Key`	For an embedded total dimension, the dimension member that is the parent of the ET key. (Required)
`Grouping ID`	For an embedded total dimension, the grouping ID (GID), which identifies the hierarchical level for a row of the dimension table. (Required)
`Parent Grouping ID`	For an embedded total dimension, the dimension member that is the parent of the grouping ID. (Required)

The parent dimension must already exist before you can create dimension attributes for it. To fully define a dimension, follow the steps listed in "Creating a Dimension".