Virtualizing data with business terms in Data Virtualization in strict virtualization mode

If you have data assets in your catalogs that are connected directly to your data sources and that have business terms assigned, in strict virtualization mode in Data Virtualization, virtual objects must use business terms for table and column names.

Before you begin

These instructions assume that you completed the following prerequisites.

Added the data source connection from which you want to virtualize to a governed catalog. For more information, see Adding a connection asset to a catalog.
Added data from your data source connection to a governed catalog. For more information, see Adding a data asset from a connection to a catalog.
Added the same data source connection that is used in the catalog to Data Virtualization. For more information, see Adding data sources.
Authored and assigned business terms to data assets that you want to virtualize in a catalog.
Enabled the strict virtualization mode in Data Virtualization. For more information, see Enabling strict virtualization mode in Data Virtualization.

About this task

If you enabled the strict virtualization mode, you can create virtual tables only from existing catalog data assets that have term assignments. Assigned terms are used to rename table and column names automatically.

In this virtualization mode, users can virtualize only assets that have been added to a catalog by using a data source connection and that have a business term assigned at the asset level and to at least one column. The same connection must be added as a data source to Data Virtualization. Use one of the following options to catalog data source assets and assign business terms:

Add data assets from the data source and assign business terms manually.
Import and enrich data assets with information and business terms that help users to understand the meaning of the data, assess its quality, and decide how to work with it. For more information about metadata import, see Importing metadata from a project (Watson Knowledge Catalog). For more information about metadata enrichment, see Managing metadata enrichment (Watson Knowledge Catalog).

In this virtualization mode, users can virtualize only assets that are added to the catalog that the user who is virtualizing the assets has access to and that has business terms that are assigned to the table and its columns.

Important: These instructions apply only if the service is set to the strict virtualization mode. To use business terms to govern your virtual data in the default virtualization mode, see Virtualizing data with business terms.

Procedure

On the navigation menu, click Data > Data virtualization.
The service menu opens to the Data sources page by default.
On the service menu, click Virtualization > Virtualize and click the Tables tab.
Data Virtualization shows only tables that you can virtualize which are tables with assigned business terms. You can see a list of business terms suggestions applicable to each table.
You can see tables in the Virtualize page only if you have the required Access catalog permission in the catalog. For more information, see Catalog collaborator permissions.
Select the table that you want to virtualize and click Add to cart.
Click View cart to view your selections.
From this window, you can update schema names or remove a selection from your cart. Additionally, you can select or deselect a column, or select a different business term for a column if multiple business terms are assigned to a table column.
To edit a table name, you can select any of the business terms that are assigned to the table. Thus, the virtual table name matches the business term that is assigned to the source table automatically.

To select columns in strict mode, follow these steps.
1. In the object action menu, click Select columns.
  
  Note: In strict mode, column names are not editable.
2. Select a business term to rename the column name.
  
  If a column has more than one business term assigned, Data Virtualization selects the first business term that was assigned to rename columns.
  
  You can select business terms to rename columns. However, you cannot edit column names in a table.
3. Select columns that you want to include in your virtual table.
  
  Note: You must select the checkbox of the column name for changes to take effect when you click Apply. Changes that you make to columns that are not selected will not take effect when you click Apply.
4. Click Apply.

Select the appropriate option to assign the virtualized table.

Assign to	When to use this option
Project	Select Project if you created the virtual table to use in a specific project. Then, choose the appropriate project. The table also appears in Virtualized data.
Virtualized data	Select Virtualized data if the table was not created to use in a specific project. This setting is the default if no projects exist.

Specify a schema in the Schema field.
You can also create a schema by following these steps.
- A Data Virtualization ManagerManagers can grant access permission on a schema to a Data Virtualization Engineer, who can pick that schema when they virtualize a table.
- If you have the Data Virtualization Engineer role, leave the Schema field as default to create a schema with your user ID.
- If you have the Data Virtualization Manager role, leave the Schema field as default to create a schema with your user ID or enter the new schema name in the Schema field.
For more information, see Creating schemas for virtual objects.
Click Virtualize to complete the process.
When the status window appears, you can select to view your virtualized data or virtualize more data.

Results

On the Virtualized data page, you can publish your virtual object to the catalog. For more information, see Publishing virtual data to the catalog in Data Virtualization.

Limitation: In the strict virtualization mode (where you can see tables only if they have at least one column with business term assignment), when you navigate to the Virtualize page, the console appears to be loading the table list for a while without showing any tables. The loading can be much slower compared to the default virtualization mode while the console evaluates the list of eligible tables that can be virtualized, depending on term assignments to data source table and column names.