13 Create and Maintain the Presentation Layer

You can learn how to use the Model Administration Tool to create, edit, and maintain objects in the Presentation layer of the Oracle BI repository.

This chapter contains the following topics:

Create and Customize the Presentation Layer

After you've created the Business Model and Mapping layer, you can drag and drop entire business models to the Presentation layer in the Administration Tool to create subject areas.

You can create subject areas and other Presentation layer objects manually.

This section contains the following topics:

About Creating Subject Areas

There are several ways to create subject areas in the Presentation layer.

The recommended method is to drag and drop a business model from the Business Model and Mapping layer to the Presentation layer, and then modify the Presentation layer based on what you want users to see. You can move columns between presentation tables, remove columns that don't need to be seen by the users, or even present all of the data in a single presentation table. You can create presentation tables to organize and categorize measures in a way that makes sense to your users.

You can also duplicate an existing subject area and its corresponding business model. See Duplicate a Business Model and Subject Area.

Although each subject area must be populated with contents from a single business model, you can create multiple subject areas for one business model. For very large business models, you may want to do this to help users work with the content. Users in Oracle BI Server can create queries that span multiple subject areas, as long as the subject areas correspond to the same business model.

There are many ways to create multiple subject areas from a single business model. One method is to drag a particular business model to the Presentation layer multiple times, then edit the properties or objects of the resulting subject areas as needed.

For example, if you've a business model called ABC that contains the Geography and Products dimensions, you can drag it to the Presentation layer twice. Two subject areas are created, with the default names ABC and ABC#1. You can then edit the subject areas as follows:

  • Rename the ABC subject area to DEF, then delete the Geography presentation hierarchy

  • Rename the ABC#1 subject area to XYZ, then delete the Products presentation hierarchy

Users in Oracle BI Server can run queries that span the DEF subject area containing the Products hierarchy, and the XYZ subject area containing the Geography hierarchy.

When you query a single subject area, all the columns exposed in that subject area are compatible with all the dimensions exposed in the same subject area. However, when you combine columns and dimensions from multiple subject areas, you must ensure that you don't include combinations of columns and dimensions that are incompatible with one another.

For example, a column in one subject area might not be dimensioned by Project. If columns from the Project dimension from another subject area are added to the request along with columns that aren't dimensioned by Project, then the query might fail to return results, or cause the Oracle BI Server error, "No fact table exists at the requested level of detail: XXXX."

Automatically Create Subject Areas Based on Logical Stars and Snowflakes

You can automatically create one subject area for each logical star or logical snowflake in your business model.

Logical stars and logical snowflakes are both composed of a centralized fact table connected to multiple dimension tables. This feature provides another way to create multiple subject areas from a single business model.

To create a subject area for each fact table that's part of a logical star or snowflake, right-click the business model and select Create Subject Areas for Logical Stars and Snowflakes. The new subject areas are automatically created, each containing a fact table and only the dimension tables with which it's associated. This option is available for any business model that contains logical stars or logical snowflakes.

About Removing Columns

One important reason to use a custom Presentation layer is to make the schema as easy to use and understand as possible.

Customize the presentation layer prevent users from seeing columns that provide no meaningful content.

The following columns are examples of columns that you might want to remove from the Presentation layer:

  • Key columns that have no business meaning.

  • Columns that users don't need to view, for example, codes, when text descriptions exist.

  • Columns that users aren't authorized to read.

Rename Presentation Columns to User-Friendly Names

You should try to keep presentation column names and their source logical column names synchronized to reduce maintenance.

By default, presentation columns have the same name as the corresponding logical column in the Business Model and Mapping layer.

To synchronize presentation column names and their source logical column names, select Use Logical Column Name in the Presentation Column dialog.

In some cases, however, you may want a different presentation column name to be shown to users. To do this, change the name of the presentation column in the Presentation Column dialog.

When you change the name of a presentation column, an alias is automatically created for the old name, so compatibility to the old name remains. See Create Aliases (Synonyms) for Presentation Layer Objects.

You can't rename a Presentation layer object to a name that's already in use as an alias for an object of the same type.

Export Logical Keys in the Subject Area

For each subject area in the Presentation layer, you can decide whether to export any logical keys as key columns to tools that access it.

Exporting logical keys is irrelevant to users of Oracle BI Presentation Services, but it may be advantageous for some query and reporting tools.

If you decide to export logical keys, make sure that the logical key columns exist in the table folders. In this situation, your business model should use logical key/foreign key joins.

When you select the option Export logical keys in the Subject Area dialog, any columns in the Presentation layer that are key columns in the Business Model and Mapping layer are listed as key columns to any ODBC client. This is the default selection. In most situations, this option should be selected.

If you're using a tool that issues parameterized SQL queries, such as Microsoft Access, don't select the option Export logical keys. This stops the tool from issuing parameterized queries.

Set an Implicit Fact Column in the Subject Area

For each subject area in the Presentation layer, you can set an implicit fact column.

The implicit fact column is added to a query when it contains columns from two or more dimension tables and no measures.

The column isn't visible in the results. It's used to specify a default join path between dimension tables when there are several possible alternatives or contexts.

If an implicit fact isn't configured, Oracle BI Server uses any fact Logical Table Source (LTS) to answer dimension-only subrequest that contains multiple dimensional references but no fact reference.

The Oracle BI Server can also use any fact LTS, if the configured implicit fact column isn't relevant to the dimensions that are joined. This could happen, for example, when implicit fact column is a level based measure at a level higher than the dimensional only subrequest.

Maintain the Presentation Layer

There is no automatic way to synchronize all changes between the Business Model and Mapping layer and the Presentation layer.

For example, if you add logical columns to an existing logical table, or edit existing columns, you must manually update the corresponding Presentation layer objects.

However, the Model Administration Tool can automatically synchronize the name of presentation columns with their corresponding logical column names. To take advantage of this feature, ensure that Use Logical Column Name is selected in the Presentation Column dialog.

In some cases, if there are many changes to a logical table or even to an entire business model, it's easiest to delete the corresponding presentation table or subject area, and then and drag and drop the updated logical objects to the Presentation layer. For this reason, it's best to wait until the Business Model and Mapping layer is relatively stable before adding customizations in the Presentation layer.

Work with Presentation Tables and Columns

Learn how to customize presentation tables and columns in these topics.

Presentation tables and presentation columns appear as folders and columns in Answers . You can customize presentation tables and presentation columns to help users craft queries based on their business needs.

This section contains the following topics:

Create and Manage Presentation Tables

You can use presentation tables to organize columns into categories that make sense to the user community.

A presentation table can contain columns from one or more logical tables. The names and object properties of the presentation tables are independent of the logical table properties. Presentation tables are created automatically by dragging and dropping logical tables from the logical layer. A presentation table can't have the same name as its parent subject area. For example, you can't have a subject area called Customer that has a Customer table within it.

Aliases are created automatically whenever presentation objects are renamed, so that any queries using the original name don't break. Use the Aliases tab to specify or delete aliases for this presentation table. See Create Aliases (Synonyms) for Presentation Layer Objects.

For localization when creating presentation tables:

  • Use the Custom display name to dynamically display a name based on a session variable.

  • Use Custom description to dynamically display a custom description based on a session variable.

  • Use the Translation Key along with the custom display name to localize the user interface.

When you externalize strings in the Presentation layer and run the Externalize Strings utility, the results contain the session variable information and the translation key. See Localize Oracle Analytics Server in Administering Oracle Analytics Server.

Use the Child Presentation Tables tab to specify presentation tables that you want to show as nested folders in Answers and BI Composer. See Nest Folders in Answers and Control Presentation Object Visibility.

See Set Permissions for Presentation Layer Objects.

  1. In the Presentation layer, from a subject area, double-click a presentation table to open the Properties dialog.
  2. Optional: In the Properties dialog for the presentation table, in the General tab, change the name for the presentation table.
  3. Leave the Hide object if field blank.
  4. Optional: In the Columns tab, add, remove, edit, or reorder the presentation columns for the selected presentation table.
  5. In the Hierarchies tab, add, remove, edit, or reorder the presentation hierarchies for the selected presentation table.
  6. When you've completed your changes, click OK.

Reorder Presentation Layer Tables

Use this task to reorder a table or sort all tables in a subject area.

  1. In the Presentation layer, double-click a subject area.
  2. In the Subject Area dialog, click the Presentation Tables tab.
  3. In the Name list, select the table and use drag-and-drop to reposition the table, or click the Up and Down buttons to move a table.
  4. Click the Name column heading to sort all tables in alphanumeric order.
    The sort operation changes the order between ascending (A to Z) and descending ( Z to A) alphanumeric order.

About Presentation Columns

Presentation columns provide analytics data for display in web clients.

You can create presentation columns by dragging and dropping logical columns from the Business Model and Mapping (logical) layer to the Presentation layer. New columns added to presentation tables can't use the same name or alias same name of an existing column.

You can drag and drop a column from a single logical table in the Business Model and Mapping layer onto multiple presentation tables. For example, you can create several presentation tables that contain different classes of measures such as one containing volume measures, one containing share measures, and one containing measures from a year ago.

You must enable the Edit presentation names in the Model Administration Tool option before you can edit the presentation column's name. See Set Administration Tool Options and Set Permissions for Presentation Layer Objects.

You can use the Custom display name, Custom description, and Translation Key fields for localization purposes. When you externalize strings in the Presentation layer and run the Externalize Strings utility, the results contain the session variable information and the translation key. See Localize Oracle Analytics Server in Administering Oracle Analytics Server.

You can use the Custom display name and Custom description fields to propagate UI hints (labels and tooltips) from an ADF data source to display in Answers . See Propagate Labels and Tooltips from ADF Data Sources.

Aliases are created automatically whenever presentation objects are renamed, so that any queries using the original name don't break.

Change the Presentation Column Name

The presentation column names, by default, are identical to the logical column names in the Business Model and Mapping layer. You can change the presentation column name.

  1. Open the Model Administration Tool.
  2. In the Presentation layer, double-click a presentation column to change.
  3. In the Presentation Column dialog, remove the check from the Use Logical Column Name field.
  4. Click Edit next to the Logical Column Name field.
  5. In the Logical Column dialog, in the Name field, type a new name to use for the Presentation Column.
  6. In the Logical Column dialog, implement other changes, and click OK.
  7. In the Presentation Column dialog, click Custom display name, and then click OK.
Reorder Presentation Columns

You can change the order of the columns in your presentation.

  1. Open the Model Administration Tool.
  2. In the Presentation layer, right-click a presentation table and select Properties.
  3. Click the Columns tab.
  4. Select the column you want to reorder.
  5. Use drag-and-drop to reposition the column, or click the Up and Down buttons.
  6. Click OK.

Nest Folders in Answers

You can designate child presentation tables using the Child Presentation Tables tab in the Presentation Table dialog.

Designate child presentation tables to give the appearance of nested folders in Answers. You can add multiple layers of nesting using this method.

The image shows how a designated child presentation table appears nested in Answers.

Description of pres_nesting.gif follows
Description of the illustration pres_nesting.gif

The folders only appear nested, but they aren't actually nested in drill-down, and the qualified names of the objects remain the same. The Presentation layer in the Administration Tool doesn't display the nesting; the nesting only appears in Answers. This feature only works for presentation tables, and not for other Presentation layer objects.

When you run a consistency check, the Consistency Check Manager detects any circularity in parent-child presentation table assignment. It also detects and reports project definitions that include child presentation tables without parent presentation tables.

If you previously used hyphens at the beginning of presentation table names or arrows at the beginning of presentation table descriptions to achieve nesting, you should run the Convert Presentation Folders utility to convert your metadata to the new structure. See Use the Convert Presentation Folders Utility.

Work with Presentation Hierarchies and Levels

Presentation hierarchies and presentation levels provide an explicit way to expose the multidimensional model in Answers .

When presentation hierarchies and levels are defined in the Presentation layer, roll-up information is displayed in the Answers navigation pane, providing users with important contextual information.

Members in a presentation hierarchy aren't visible in the Presentation layer. You can see hierarchy members in Answers .

Users can create hierarchy-based queries using objects in presentation hierarchies and levels. Presentation hierarchies expose analytic functionality such as member selection, custom member groups, and asymmetric queries.

You can also provide localization information and apply fine-grained access control to presentation hierarchies and levels.

If you've a repository from a previous release, the presentation hierarchies don't appear in the Presentation layer automatically as part of the Oracle BI repository upgrade process. You must manually create the presentation hierarchies and levels objects by dragging logical dimensions from the Business Model and Mapping layer to the appropriate presentation tables.

This section contains the following topics:

Create and Manage Presentation Hierarchies

To create a presentation hierarchy, you can drag a logical dimension hierarchy from the Business Model and Mapping layer to a table in the Presentation layer.

The presentation hierarchy object must be located within a presentation table, unlike in the Business Model and Mapping layer, where logical dimensions are peer objects of tables. Presentation hierarchies are also displayed within their associated tables in Answers , providing a conceptually simpler model.

If a logical dimension spans multiple logical tables in the Business Model and Mapping layer, it's a best practice to model the separate logical tables as a single presentation table in the Presentation layer.

There are several ways to create presentation hierarchies:

  • When you drag an entire business model to the Presentation layer, the presentation hierarchies and constituent levels appear automatically, along with other presentation objects.

  • When you drag a logical dimension table to the Presentation layer, presentation hierarchies and levels based on those dimensions are created automatically.

  • You can also drag individual logical dimensions to the appropriate presentation tables to create corresponding presentation hierarchies within those tables.

  • As with most other objects in the repository, you can right-click a presentation table, select New Object, and then select Presentation Hierarchy to manually define the object.

You can also drag an individual logical level from the Business Model and Mapping layer to a presentation table to create a presentation hierarchy that's a subset of the logical dimension hierarchy.

For example, suppose a logical dimension has the levels All Markets, Total US, Region, District, Market, and Market Key. Dragging and dropping the entire logical dimension to the corresponding presentation table appears as follows:

Description of p_hier_total.gif follows
Description of the illustration p_hier_total.gif

However, dragging and dropping the Region level to the same presentation table appears as follows:

Description of p_hier_sub.gif follows
Description of the illustration p_hier_sub.gif
Model Dimensions with Multiple Hierarchies in the Presentation Layer

For logical dimensions that contain multiple logical hierarchies, multiple separate presentation hierarchies are created.

For example, the following logical dimension called Product contains the two hierarchies Category and Country:

Description of p_hier_peer1.gif follows
Description of the illustration p_hier_peer1.gif

In the Business Model and Mapping layer, this logical dimension is modeled as a single dimension object that contains multiple hierarchies. In contrast, the Presentation layer models this dimension as two separate objects: one that displays the drill path through the Category level, and another that shows the drill path through the Country level, as follows:

Description of p_hier_peer2.gif follows
Description of the illustration p_hier_peer2.gif
Edit Presentation Hierarchy Objects

Learn how to edit presentation hierarchy properties.

You can edit presentation hierarchy properties, including setting permissions to apply role-based access control, setting a custom display name for localization purposes, and changing the levels in a hierarchy.

The Display Columns tab is only available for parent-child hierarchies. Because parent-child hierarchies don't contain levels, display columns are defined for the presentation hierarchy object as a whole. Use the Display Columns tab to define which columns should be used for display for this parent-child hierarchy.

You can add, delete, or reorder display columns. You can also click the Edit button to edit properties for a particular column.

The Levels tab lists the levels within the hierarchy and their order. This tab isn't available for parent-child hierarchies. You can add, delete, or reorder levels. You can also click the Edit button to edit properties for a particular level. See Create and Manage Presentation Levels.

See Set Permissions for Presentation Layer Objects.

Use the Aliases tab to specify or delete aliases for this presentation hierarchy. See Create Aliases (Synonyms) for Presentation Layer Objects.

See Control Presentation Object Visibility and Localize Oracle Analytics Server in Administering Oracle Analytics Server.

  1. In the Presentation layer, double-click a presentation hierarchy to display the Presentation Hierarchy dialog.
  2. In the General tab, you can change the following:

    • Name. Aliases are created automatically whenever presentation objects are renamed, so that any queries using the original name don't break.

      You must enable the Edit presentation names Administration Tool option before you can edit the presentation hierarchy's name.

    • Permissions.

    • Custom display name and Custom description. Select Custom display name to dynamically display a name based on a session variable and to edit the Translation Key field. Select Custom description to dynamically display a custom description based on a session variable.

      These options are used typically for localization purposes. When you externalize strings in the Presentation layer and run the Externalize Strings utility, the results contain the session variable information and the translation key.

    • Logical Dimension. This field displays the name of the logical dimension for this presentation hierarchy. Click Browse to select a different logical dimension.

    • Hide object if. This field lets you specify an expression that controls whether this presentation hierarchy is visible in the Subject Area Tree in Answers and BI Composer. Leave this field blank (the default) to show the object.

Create and Manage Presentation Levels

Presentation levels are typically created automatically when presentation hierarchies are created.

Presentation levels are displayed within hierarchical columns in Answers .

See the following:

You must enable the Edit presentation names Administration Tool option before you can edit a presentation level's name.

Aliases are created automatically whenever presentation objects are renamed, so that any queries using the original name don't break.

The Logical Level field displays the name of the logical level for this presentation level.

The Custom display name and the Custom description options are used typically for localization purposes. When you externalize strings in the Presentation layer and run the Externalize Strings utility, the results contain the session variable information and translation key.

Specifying an expression in the Hide object if field has no effect on the visibility of presentation levels in the Subject Area Tree in Answers and BI Composer.

The Drill To Levels and Drill From Levels tabs, and the Generate Drill Graph aren't currently used.

Use the Display Columns tab to define columns used for display for that level on drill-down. For example, if two columns called Name and ID at the same level, you can choose to display Name because it's the more user-friendly option. The display columns that appear by default when a presentation level is created are based on which key columns for the corresponding logical level have the Use for display option selected.

You can add, delete, or reorder display columns. You can also click the Edit button to edit properties for a particular column.

  1. In the Presentation layer, double-click a presentation level to display the Presentation level dialog.
  2. In the General tab, type a Name for the presentation level.
  3. Click Permissions to specify access to the presentation level by application roles and users.
  4. Optional: Select Custom display name to dynamically display a name based on a session variable and to edit the Translation Key field.
  5. Optional: Select Custom description to dynamically display a custom description based on a session variable.
  6. Optional: Click Browse to select a different Logical Level.
  7. Drag a presentation column to the presentation level in the Presentation layer to automatically add the column as a display column for the presentation level.
  8. In the Aliases tab to specify or delete aliases for a presentation level.

Set Permissions for Presentation Layer Objects

You can apply access control to restrict which individual users or application roles (groups) can access particular presentation layer objects.

For example, you can provide read-only access to a set of presentation tables for a particular application role, read-write access for a second application role, and no access for a third application role.

You can also use the Identity Manager to set up privileges and permissions. The Identity Manager is useful for setting permissions for individual application roles to many objects at once, unlike permissions in the Presentation layer, which you can only set for one object at a time. See Set Up Object Permissions and Apply Data Access Security to Repository Objects.

You can control what level of privilege is granted by default to the AuthenticatedUser application role, which is the default application role associated with new repository objects. To do this, set the DEFAULT_PRIVILEGES parameter in the NQSConfig.INI file.

To set permissions for presentation layer objects:

  1. In the Presentation layer, double-click a presentation object, such as a subject area, table, column, or hierarchy.
  2. In the General tab, click Permissions.
  3. In the Permissions dialog, any users or application roles with the Default permission don't appear in the User/Application Roles list. Select Show all users/application roles to see users and application roles with the Default permission.

    In online mode only, by default, no users are retrieved, even when Show all users/application roles is selected. Click Set online user filter to specify the set of users you want to retrieve.

    The filter is empty by default, which means that no users are retrieved. Enter * to retrieve all users, or enter a combination of characters for a specific set of users, such as A* to retrieve all users whose names begin with the letter A. The filter isn't case-sensitive.

  4. For each user and application role, you can allow or disallow access privileges for this presentation object by selecting one of the following options:

    • Read. Only allows read access to this object.

    • Read/Write. Provides both read and write access to this object.

    • No Access. Explicitly denies all access to this object.

    • Default. The permission is inherited from the parent object. For subject areas, because they're a top-level object, Default is equivalent to the permission granted to the AuthenticatedUser application role.

  5. Click OK.
  6. Click OK in the Properties dialog for this presentation object.

Generate a Permission Report for Presentation Layer Objects

You can generate a permission report for individual presentation layer objects to see a summary of how permissions have been applied for that object.

The Permission Report displays the name and a description of the presentation object, along with a list of users/application roles and their permissions.

  1. In the Model Administration Tool, open a repository in online or offline mode.
  2. In the Presentation layer, right-click an object and select Permission Report.

Sort Columns in the Permissions Dialog

There are six ways that you can sort the types and User/Application Role names in the Permissions dialog.

To change the sort, click the heading of the first or second column. The first column has no heading and contains an icon that represents the type of user or application role. The second column contains the name of the User/Application Role object.

You can't sort on the columns for individual object permissions such as Read, and Read/Write.

There are three ways to sort by type, and two ways to sort the list of user and application role names. This results in a total of six possible sort results (3 x 2 = 6). The following list shows the sort results available by clicking the type column:

  • AuthenticatedUser, Application Roles, Users, ascending by name of type

  • Users, Application Roles, AuthenticatedUser, descending by name of type

  • Type column is in no particular order. The Type value is ignored, as all names in User/Application Role column are sorted in ascending order by value in User/Application Role column.

The following list shows the sort results available by clicking the User/Application Role column:

  • Ascending within the type

  • Descending within the type