Work with Presentation Tables and Columns

This topic provides information about how to create and modify the presentation layer's tables and columns.

Topics:

About Presentation Tables

Subject areas contain presentation tables, and presentation tables contain presentation columns and presentation hierarchies. Presentation tables function as intuitive categories that collocate the columns and data users need to create visualizations and analyses.

In most cases, you create presentation tables by dragging and dropping logical tables from the logical layer into a presentation layer's subject area. The names and object properties of the presentation tables are independent of the logical table properties.

In most cases, a presentation table contains columns from its corresponding logical table. But you can build a presentation table containing columns from a different logical table within the same business model. In such cases, be aware that building a presentation table in this way can cause query errors when a user selects these columns.

Create a Presentation Table

Manually create a presentation table when you can't drag and drop a table from the logical layer to the presentation layer.

You can select the Hide if field and write an expression to hide a presentation table. See Write an Expression to Hide a Presentation Object.

Semantic Modeler doesn't create an alias when you change a presentation table's name. If you need to track a table's previous names, then Oracle recommends that you use the Alternative Names field to create and manage alternative names for the table. For more information about alternative names, see About Alternative Names for Presentation Objects.

On the Home page, click Navigator and then click Semantic Models.
In the Semantic Models page, click a semantic model to open it.
Click Presentation Layer.
In the Presentation Layer pane click Create and then click Create Presentation Table.
In Create Presentation Table, go to the Name field and enter a presentation table name.
Go to Subject Area and select which subject area to add the table to.
Click OK.
In the presentation table, click General to set the presentation table's general properties.
Optional: In the Description field, enter a description that is displayed when a user creating visualizations or analyses hovers over the table in the subject area.
Optional: In the Alternative Names field, enter an alternative name for the presentation table.
Optional: Select the Hide if field and provide an expression that controls whether the presentation table is available to users when they create visualizations and analyses.
Click Save.

About Presentation Columns

Presentation columns provide the data users need to create visualizations and analyses.

Presentation columns can be either attribute columns or measure columns. Attribute columns contains columns from dimension logical tables with a GROUP BY and DISTINCT clause applies, and measure columns which are numeric columns are from fact logical tables with an aggregation function like SUM applied.

In most cases, you create presentation columns by dragging and dropping logical columns from the logical layer to a presentation table. Columns that you drag and drop must have unique names. But in some cases when you can't drag and drop logical columns to a presentation table, you can manually create presentation columns within a presentation table.

You can drag and drop a column from a logical table into 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.

Create a Presentation Column

Manually create a presentation column when you can't drag and drop a column from the logical layer to the presentation layer.

You can select the Hide if field and write an expression to hide a presentation column. See Write an Expression to Hide a Presentation Object.

On the Home page, click Navigator and then click Semantic Models.
In the Semantic Models page, click a semantic model to open it.
Click Presentation Layer.
In the Presentation Layer pane locate and double-click the presentation table that you want to add a column to.
In the presentation table, click Columns and then click Add Column.
In the New Column table row, enter a name for the column and press Enter.
Confirm that the new column is highlighted in the table, and then click Detail view.
Optional: In the Description field, enter a description that is displayed when a user creating visualizations or analyses hovers over the column in the subject area.
Go to Logical Column, click Select, and select which logical column to associate the presentation column with.
Optional: Select the Hide if field and provide an expression that controls whether this column is available to users when they create visualizations and analyses.
Click Save.

Modify a Presentation Column Name

When you drag and drop a logical table or logical columns to the presentation layer, by default the resulting presentation columns have the same names as the logical columns they're based on. You can change a presentation column's default name to a more user-friendly name.

Semantic Modeler doesn't create an alias when you change a presentation column's name. If you need to track a column's previous names, then Oracle recommends that you use the Alternative Names field to create and manage alternative names for the column. For more information about alternative names, see About Alternative Names for Presentation Objects.

On the Home page, click Navigator and then click Semantic Models.
In the Semantic Models page, click a semantic model to open it.
Click Presentation Layer.
In the Presentation Layer pane locate and expand the presentation table containing the column to rename. Double-click the column.
In Name, enter a new name for the column.
Optional: In Alternative Names, type an alternative name and press Enter. Repeat this step to add more alternative names for the column.
Click Save.

Delete a Presentation Column

Remove presentation columns that don't provide meaningful content to the users who create visualization and analyses.

Consider removing these types of presentation columns from presentation tables:

Key columns that have no business meaning.
Columns that users don't need to view. For example, a product code column when its text descriptions exist in another column.
Columns that users aren't authorized to read.

On the Home page, click Navigator and then click Semantic Models.
In the Semantic Models page, click a semantic model to open it.
Click Presentation Layer and locate and double-click the presentation table that you want to remove columns from.
In the presentation table, click Columns.
Click the column that you want to remove, click Row menu, and then click Delete.
Click Save.

Reorder and Nest Tables for End Users

You can specify the order and levels that a subject area's tables display to users who access the subject area to create visualization and analyses.

You can move a presentation table up or down to change its position in the subject area, and you can change the table's relationship to the other tables in the subject area by moving the table right or left. Moving tables right and left provides the end user with nested folders in the subject area.

Changing the table order doesn't change the order that the presentation tables display in the Semantic Modeler's Presentation Layer pane. The table order and nesting you specify only appears in the subject area's Tables tab and the subject area that end users access. The tables aren't actually nested in drill-down, and the qualified names of the objects remain the same.

When you run consistency check on the subject area, the consistency check detects any circularity in parent-child presentation table assignments. It also detects and reports project definitions that include child presentation tables without parent presentation tables.

On the Home page, click Navigator and then click Semantic Models.
In the Semantic Models page, click a semantic model to open it.
Click Presentation Layer.
In the Presentation Layer pane locate and double-click the subject area where you want to reorder the tables for end users.
In Tables click a table to select it and use the Move Up, Move Down, Move Right, and Move Left buttons to change its position.
Click Save.