Understanding Level Attributes

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

A level attribute is a child entity of a level and a dimension attribute. A level attribute stores descriptive information about its related level. For example, a level containing product identifiers might have an associated level attribute that contains color information for each product.

Each level attribute maps to a column in a dimension table. The level attribute column must be in the same table as the column (or columns) for its associated level. Level attributes are fully described in "OLAP Metadata Model".

Use the procedures in the CWM2_OLAP_LEVEL_ATTRIBUTE package to create, drop, and lock level attributes, to assign level attributes to levels and dimension attributes, and to specify descriptive information for display purposes.

Several level attribute names are reserved, because they have special significance within CWM2. Reserved level attributes are associated with reserved dimension attributes of the same name. Reserved level attributes will be mapped to columns containing specific information. The reserved level attributes are listed in Table 22-1.

Table 22-1  Reserved Level 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 at the lowest level in a row of the dimension table.
Parent ET Key	For an embedded total dimension, the dimension member that is the parent of the ET key.
Grouping ID	For an embedded total dimension, the grouping ID (GID), which identifies the hierarchical level for a row of the dimension table.
Parent Grouping ID	For an embedded total dimension, the dimension member that is the parent of the grouping ID.

The parent dimension, parent level, and parent dimension attribute must already exist in the OLAP Catalog before you can create a level attribute.