To remove a column mapping, click the Delete button. You might need to scroll to In the Logical Table Source list, select a source and click Unmap. Click OK.

10-6 Metadata Repository Builders Guide for Oracle Business Intelligence Enterprise Edition the measure object. Another example is using CAST to transform a column of type TIMESTAMP to type DATE for faster display in Answers and other clients for example, CASTDB..TABLE.COL AS DATE. You can also conform sources by creating expressions that perform transformations on physical data. For example, you can use the CAST function to transform a column with a character data type to an integer data type, to match data coming from a second logical table source. Other examples include using CONCATENATE or math functions to make similar transformations on physical data. See Creating Derived Columns for calculations that need to occur post-aggregation.

7. To remove a column mapping, click the Delete button. You might need to scroll to

the right to locate the Delete button. 8. After you map the appropriate columns, click OK. Unmapping a Logical Column from Its Source In the Logical Column dialog, the Column Source tab contains information about the logical column. You can edit the logical table sources from which the column derives its data, or unmap it from its sources. To unmap a logical column from its source: 1. In the Business Model and Mapping layer of the Administration Tool, double-click a logical column. 2. In the Logical Column dialog, click the Column Source tab.

3. In the Logical Table Source list, select a source and click Unmap.

4. Click OK.

Defining Content of Logical Table Sources To use a source correctly, the Oracle BI Server has to know what each source contains in terms of the business model. Therefore, you need to define aggregation content for each logical table source of a fact table. The aggregation content rule defines at what level of granularity the data is stored in this fact table. For each dimension that relates to this fact logical table, define the level of granularity, making sure that every related dimension is defined. See Setting Up Aggregate Navigation by Creating Sources for Aggregated Fact Data for more information. If a logical table is sourced from a set of fragments, it is not required that every individual fragment maps the same set of columns. However, the server returns different answers depending on how columns are mapped. ■ If all the fragments of a logical table map the same set of columns, than the set of fragmented sources is considered to be the whole universe of logical table sources for the logical table. This means that measure aggregations can be calculated based on the set of fragments. ■ If the set of mapped columns differ across the fragments, than the Oracle BI Server assumes that it does not have the whole universe of fragments, and therefore it would be incorrect to calculate aggregate rollups since some fragments are missing. In this case, the server returns NULL as measure aggregates. Managing Logical Table Sources Mappings 10-7 Use the Content tab of the Logical Table Source dialog to define any aggregate table content definitions, fragmented table definitions for the source, and WHERE clauses if you want to limit the number of rows returned. See Setting Up Fragmentation Content for Aggregate Navigation for additional information. Verifying that Joins Exist from Dimension Tables to Fact Table This source content information tells the Oracle BI Server what it needs to know to send queries to the appropriate physical aggregate fact tables, joined to and constrained by values in the appropriate physical aggregate dimension tables. Be sure that joins exist between the aggregate fact tables and the aggregate dimension tables in the Physical layer. One recommended way to verify joins is to select a fact logical table and open a Business Model Diagram Selected Tables and Direct Joins. Only the dimension logical tables that are directly joined to this fact logical table appear in the diagram. It does not show dimension tables if the same physical table is used in logical fact and dimension sources. Figure 10–3 shows an example of how the Fact - Assess fact logical table appears in a Business Model Diagram Selected Tables and Direct Joins view. Figure 10–3 Business Model Diagram of Direct Joins for a Fact Table Table 10–1 contains a list of the logical level for each dimension table that is directly joined the Fact - Assess fact table shown in Figure 10–3 . Note: It is recommended that all the fragments map the same set of columns. Table 10–1 Dimension and Logical Level as Shown in Content Tab Dimension Logical Level Account Geography Postal Code Detail Person Geography Postal Code Detail 10-8 Metadata Repository Builders Guide for Oracle Business Intelligence Enterprise Edition To create logical table source content definitions: 1. In the Business Model and Mapping layer of the Administration Tool, double-click a logical table source. 2. In the Logical Table Source dialog, click the Content tab and perform the following steps using Table 10–2 as a guide. 3. If a logical source is an aggregate table and you have defined logical dimensions, select Logical Level from the Aggregation content, group-by list. Then, in the Logical Level list, select the appropriate level for each logical dimension table to which the logical fact table is joined. You should specify a logical level for each dimension, unless you are specifying the Grand Total level. Dimensions with no level specified are interpreted as being at the most detailed level.

4. To specify fragmented table definitions for the source, use the Fragmentation