Administering Maps

Before content designers can create map views, you as the administrator must specify layers and maps and configure the metadata.

This section discusses the following:

• Working with Maps and Layers

• Administration Page Functions

• Administering Maps Using Administration Pages

• Handling the Translation of Layers in Maps

Working with Maps and Layers

Maps can have one or more layers with which to work.

The first step is to select the layers for use on maps. An administrator has configured layers using the Map Builder tool of Oracle Spatial. You next select at least one map from a list of those that an administrator has configured using the Map Builder tool of Oracle Spatial. This map becomes the background on which the layers are applied. You can optionally specify images for use with map formats. This section provides the following information about maps and layers:

• Associating Layers with Columns

• Ordering Layers on Maps

• Changes to Spatial Metadata Require Restart

Associating Layers with Columns

After selecting layers and maps, you can associate certain layers with columns in the Oracle Business Intelligence subject area folders.

If the association between a column and a layer is incorrect, then the layer cannot be displayed correctly on the map. The association ensures that shape definitions can be found in the database for the column values during map rendering. You must ensure that a shape geometry definition exists for each column value in the database. If a shape geometry definition does not exist for a particular column value, then the shape cannot be shown on the map and might inhibit user interactions on the map.

Shape lookup is based on the column values, and column-to-layer mapping is independent of locale or language. Therefore, you must ensure that the spatial column that is being associated with a layer does not itself have values that are affected by locale or language. To ensure this association, do one of the following:

• Model spatial columns as double columns in the business modeling layer, which is the recommended method.

• Create special spatial columns that have values that do not change across locale or language. You must ensure that content designers are not confused seeing these special columns in the Subject Areas pane when working with analyses.

If you decide to use double columns, then see Metadata Repository Builder's Guide for Oracle Business Intelligence Enterprise Edition for more information on double columns. The advantages of using double columns are the following:

• You can provide code values (that is, descriptor IDs) for each shape definition and at the same time show display values (that is, descriptor values) according to locale or language.

• Code values are passed only as layer key values for lookup.

• You eliminate the need for the complex joining of various columns to uniquely locate the shape. For example, a layer geometry table might contain multiple cities with the name of London. To uniquely distinguish these cities, you might use a pattern of Country_State_City, as in US_Kansas_London or Canada_Ontario_London. The problem with this approach is that it might require three separate columns to be grouped, joined by a delimiter (such as an underscore), and associated with a layer. This association requires the content designer to select three columns (Country, State, City) in the criteria to create a single layer.

A BI layer can be associated with multiple columns in multiple subject areas. You must ensure that a layer is associated with at least one spatial column. If the layer association is missing, then the map might not be updated when a user drills on the mapped BI column. You can also have feature layers, which are layers that are not associated with a BI column.

Ordering Layers on Maps

The ordering of map layers is very important. You must pay close attention to ensure that users have a seamless experience while navigating on the map (that is, drilling and zooming).

In the Edit Background Map dialog, you assign each layer a minimum and maximum zoom range. Given that the map zoom slider can slide only from bottom to top vertically, the layers with lower minimum zoom levels are placed at the bottom of the slider. Ensure that the layer grid on the Interactive BI Layers section of the dialog follows a similar pattern, so that you place layers with lower minimum zoom levels at the bottom of the list. Ensure the following:

• That you sort the layers (by clicking the sort icon) before closing the dialog.

• That BI layers are ordered higher than non-BI layers. If a non-BI layer is ordered higher than any BI layers, then the non-BI layer is displayed on top of the lower BI layers on the map, which prevents the BI layers from being interactive.

Layer ordering becomes irrelevant when the zoom ranges of layers do not intersect on the scale. Ordering becomes very important when layers have a common minimum and maximum zoom range. Use care to ensure that detailed layers are not hidden by the aggregated layers during drilling or zooming operations.

Description of the illustration GUID-67F49FDB-AFD7-440F-8542-F5D78E73B613-default.gif

Description of the illustration GUID-E062AE66-47D2-47AD-9053-220E984AB617-default.gif

The layer ordering at zoom level 4 is unclear, because multiple layers can be shown. Because of the layer order that is specified in the Interactive BI Layers section of the dialog, the map renders with the following order at zoom level 4: Country, Sate, and City (reading from bottom to top).

If the layers are not ordered properly in the dialog, then you can re-order layers by clicking the Move Down and Move Up buttons on the zoom grid of the dialog, or by clicking the Sort Layers by Zoom Level button.

See User's Guide for Oracle Business Intelligence Enterprise Edition for more information about layers.

Example 12-1 World Map with Three Layers

Suppose that a world map has three layers (Country, State, and City) and 15 zoom levels defined on it. The Country layer has a minimum and maximum zoom range of 0-5, the State layer range is 6-10, and the City layer range is 11-15. As the user navigates from the minimum to the maximum zoom level on the map, the layer order (also known as the visual order) is displayed as Country, State, and City.

The first image above shows the Edit Background Map dialog with the Interactive BI Layers section specified for this example. Reading from bottom to top, you see the layer order in that section as Country, State, and City.

Example 12-2 World Map with Common Levels

Consider the same world map with layers that have common zoom ranges. Suppose that the user zooms to level 4 on the map that corresponds to the Edit Background Map dialog that is shown in the second image above. Notice that all three layers include zoom level 4.

Changes to Spatial Metadata Require Restart

An administrator can edit the spatial metadata that is stored in the Oracle Database and accessed by MapViewer.

For example, an administrator can add a new layer. These edits are not visible on the Oracle BI Server Administration pages for managing maps until MapViewer is restarted and so refreshed with the latest updates.

Administration Page Functions

The Oracle BI Server Administration page provides the Manage Map Data link.

This link displays the Manage Map Data page, where you can manage the logical and display versions of the data from various physical data sources. This defines the layers that content designers use when creating map views. The data that is available for managing maps and data is stored in Oracle Database as part of MapViewer.

Using this page, you provide:

• Logical names to prevent any existing BI column mappings and map analyses from breaking because of changes to the physical data or to the data source.

• Display names so that the geographic data is meaningful to end users.

Administering Maps Using Administration Pages

This section assumes that you installed Oracle BI Enterprise Edition and that Oracle MapViewer was automatically configured and deployed.

For information on MapViewer, see User's Guide for Oracle MapViewer.

To administer maps using Administration pages:

1. Sign in to Oracle Business Intelligence.

   Ensure that you have been granted the Access to Administration and Manage Map Data privileges.

2. In the global header, click Administration.
3. Click the Manage Map Data link to display the Manage Map Data page.
4. Click the Layers tab.
5. Click the Import Layers button to display the Import Layers dialog.
6. In the dialog, select the connection and the layers that are needed for zooming and drilling. (This tab is not prepopulated by other selections on the Administration pages. You can use any layers or images with any map.)

   Click OK when you have finished selecting layers that are appropriate for the subject area with which you are working.

7. Back on the Layers tab, select a layer, then click the Edit Layer button to display the Edit Layer dialog in which you associate layers with attribute columns so that you can display BI data in the map view.

   Click OK when you have finished editing the layer.

   You use this tab to associate layers with BI data. If you use the City column in multiple subject areas, then you must associate it with a layer for each subject area.

8. Click the Background Maps tab, then click the Import Background Maps button to display the Import Background Map dialog.
9. In the dialog, select the connection and the main maps to use.

   The connection that you select for the main map can be different from the connection for the layers or images.

   Click OK when you have finished selecting main maps.

10. Back on the Background Maps tab, select a map, then click the Edit Background Map button to display the Edit Background Map dialog in which you name the map and specify the order of layers and their zoom levels.

    Click OK when you have finished editing the map.

11. Optionally, click the Images tab, then click the Import Images button to display the Import Images dialog. You can import images if you plan to use them as a format on maps.
12. In the dialog, select the connection and the images to use.

    Click OK when you have finished selecting images.

13. Click Back when you have finished working with the Administration page. Your changes are saved automatically.

After you have specified background maps, layers, and zoom levels, MapViewer creates a static image for a map using this information. Then MapViewer sends that image for rendering in the browser for use by content designers and end users in map views.

Handling the Translation of Layers in Maps

You can use the functionality of MapViewer to label the features of a theme (called a layer for maps in Oracle BI EE) using a specific language or locale.

To configure these translated labels for maps, use the information that is provided in User's Guide for Oracle MapViewer.