Start the Virtuoso Web User Interface

Figure8.13.Start

Select the "Conductor" link in the Left Frame and Login as the "dba" user.

Figure8.14.Conductor

Select the "Databases" -> "External Data Source" -> "Data Sources" tab menu items

Figure8.15.Databases

Select the "Connect" button for the "ora10ma" Oracle DSN.

Figure8.16.Connect

On successful connection Select the "Link Objects" button to obtain a list of available tables

Figure8.17.Link Objects

Select all the tables that are part of the "HR" catalog.

Figure8.18.Select all tables

Change the Catalog for each table to be "HR" using the "Set All" button.

Figure8.19.Catalog

Ensure a primary key is assigned to all table that are to be used in the EDM generation phase.

Figure8.20.Primary Key

Select the "Link" button to link the selected tables into Virtuoso

Figure8.21."Link" button

On completion of the Link process the tables will be displayed in the "External Linked Objects" tab.

Figure8.22.Completion

The linked tables can be queried by clicking on the hyperlink in the "Local Name" column of the "External Linked Objects" tab above, which loads the Virtuoso "Interactive SQL" interface with the required SQL "Select" for retrieving the remote table data . We shall use the "HR.ora10ma.COUNTRIES" table to demonstrate this.

Figure8.23.Querying

Then click the "Execute" button to run the query and retrieve the results from the remote table.

Figure8.24.Execute

The tables can also be viewed as part of the Virtuoso "SQL Schema Objects" under the "HR" catalog name.

Figure8.25.SQL Schema Objects

The Link process is now complete enabling the tables to be queried as if part of the Virtuoso Schema.