Select the option Derived from existing columns using an expression. Click the Expression Builder button to open Expression Builder. Click OK. Edit any logical columns that display currency values to use the appropriate

Working with Logical Tables, Joins, and Columns 8-13 You can make some changes in this dialog. If you make changes, click OK to accept the changes instead of Cancel.

4. In the Browse dialog, click OK.

Enabling Double Column Support by Assigning a Descriptor ID Column When multilingual columns are based on a lookup function, it is common to specify the non-translated lookup key column as the descriptor ID column of the translated column. Assigning a descriptor ID column enables Double Column Support, a feature which helps in defining language-independent filters. For example, in Answers, users see the display column, but the query filters on the hidden descriptor ID column. For more information, see Supporting Multilingual Data in Oracle Fusion Middleware System Administrators Guide for Oracle Business Intelligence Enterprise Edition. Note that double columns are also used for other purposes, like modeling spatial columns. To assign a Descriptor ID column to a display column: 1. In the Logical Column dialog, in the General tab, click Set next to the Descriptor ID column field. 2. In the Browse dialog, select a key column.

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

column, and then click Cancel. You can make some changes in this dialog. If you make changes, click OK to accept the changes instead of Cancel. 4. In the Browse dialog, click OK. Creating Derived Columns Some columns are derived from other logical columns as a way to apply post-aggregation calculations to measures. To do this, you specify the derived column expression in the Column Source tab of the Logical Column dialog. You can also create a set of derived columns using the Calculation Wizard. See Using the Calculation Wizard for more information. Note that if the parameter PREVENT_DIVIDE_BY_ZERO is set to YES in NQSConfig.INI, the Oracle BI Server prevents errors in divide-by-zero situations, even for Answers column calculations. The Oracle BI Server creates a divide-by-zero prevention expression using nullif or a similar function when it writes the physical SQL. Because of this, you do not have to use CASE statements to avoid divide-by-zero errors, as long as PREVENT_DIVIDE_BY_ZERO is set to YES the default value. See Oracle Fusion Middleware System Administrators Guide for Oracle Business Intelligence Enterprise Edition for more information about NQSConfig.INI settings. You can also apply calculations pre-aggregation. See Defining Physical to Logical Table Source Mappings and Creating Calculated Items for more information. To specify a derived column: 1. In the Logical Column dialog, select the Column Source tab.

2. Select the option Derived from existing columns using an expression.

3. Click the Expression Builder button to open Expression Builder.

8-14 Metadata Repository Builders Guide for Oracle Business Intelligence Enterprise Edition 4. In the Expression Builder - Derived logical column dialog, specify the expression from which the logical column should be derived.

5. Click OK.

Note that you can display data from multilingual database schemas by using Expression Builder to create a lookup function. For more information, see Supporting Multilingual Data in Oracle Fusion Middleware System Administrators Guide for Oracle Business Intelligence Enterprise Edition. Configuring Logical Columns for Multicurrency Support You can configure logical columns so that Oracle Business Intelligence users can select the currency in which they prefer to view currency columns in analyses and dashboards. You can set up this feature so that all users see the same static list of currency options, or you can provide a dynamic list of currency options that changes based on a Logical SQL statement you specify. To configure logical columns for multicurrency support: 1. Create a session variable named PREFERRED_CURRENCY, along with an initialization block to use in the variable. Make sure to select Enable any user to set the value when you create the session variable. Note that when you use session variables in an expression for Oracle BI Presentation Services, you must preface their names with NQ_SESSION. See Creating Session Variables and Creating Initialization Blocks for detailed information about setting up session variables and initialization blocks.

2. Edit any logical columns that display currency values to use the appropriate

conversion factor using the PREFERRED_CURRENCY session variable. To do this, double-click the appropriate logical column in the Business Model and Mapping layer, select the Column Source tab, and create a derived expression that uses the PREFERRED_CURRENCY variable. For example, the following logical column expression uses the value of the NQ_ SESSION.PREFERRED_CURRENCY variable to switch between different currency columns. Note that the currency columns are expected to have the appropriate converted values. INDEXCOL CASE VALUEOFNQ_SESSION.PREFERRED_CURRENCY WHEN gc1 THEN 0 WHEN gc2 THEN 1 WHEN orgc THEN 2 WHEN lc1 THEN 3 ELSE 4 END, Paint.Sales Facts.USDCurrency, Paint.Sales Facts.DEMCurrency , Paint.Sales Facts.EuroCurrency , Paint.Sales Facts.JapCurrency , Paint.Sales Facts.USDCurrency

3. If you want to provide a dynamic list of currency options, create a table in your