Optionally, you can assign a different column on which to base the sort order for a Optionally, you can assign a descriptor ID column for this column. See Optionally, on the Column Source tab, you can specify that this logical column is Optionally, on the

8-12 Metadata Repository Builders Guide for Oracle Business Intelligence Enterprise Edition Creating Logical Columns The following procedure explains how to create logical columns in the Business Model and Mapping layer. To create a logical column: 1. In the Business Model and Mapping layer, right-click a logical table.

2. From the shortcut menu, select New Object, then select Logical Column.

3. In the General tab, type a name for the logical column.

The name of the business model and the associated logical table appear in the Belongs to Table field.

4. Select Writeable to enable write back for this column. See

Enabling Write Back On Columns for more information.

5. Optionally, you can assign a different column on which to base the sort order for a

column. See Basing the Sort for a Logical Column on a Different Column for details.

6. Optionally, you can assign a descriptor ID column for this column. See

Enabling Double Column Support by Assigning a Descriptor ID Column for details.

7. Optionally, on the Column Source tab, you can specify that this logical column is

derived from other logical columns. See Creating Derived Columns for details.

8. Optionally, on the Aggregation tab, you can set column aggregation. See

Setting Default Levels of Aggregation for Measure Columns for details.

9. Optionally, on the Levels tab, you can associate attributes with a logical level.

Measures can be associated with levels from multiple dimensions and always aggregate to the levels specified. See Associating an Attribute with a Logical Level in Dimension Tables for details.

10. Click OK.

Basing the Sort for a Logical Column on a Different Column For a logical column, you can specify a different column on which to base the sort. This changes the sort order of a column when you do not want to order the values lexicographically. Lexicographical sort arranges the results in alphabetic order such as in a dictionary. In this type of sort, numbers are ordered by their alphabetic spelling and not divided into a separate group. For example, if you sorted on month using a column such as MONTH_NAME, the results would be returned as February, January, March, and so on, in lexicographical sort order. However, you might want months to be sorted in chronological order. Therefore, your table should have a month key such as MONTH_KEY with values of 1 January, 2 February, 3 March, and so on. To achieve the desired sort, you set the Sort order column field for the MONTH_NAME column to be MONTH_KEY. Then, a request to order by MONTH_NAME would return January, February, March, and so on. To assign a different column on which to base the sort order for a column: 1. In the Logical Column dialog, in the General tab, click Set next to the Sort order column field. 2. In the Browse dialog, select a column.

3. To view the column details, click View to open the Logical Column dialog for that