Managing multiple connections to the same data source

When a data source with multiple connections is queried, an ambiguous connection condition can result. You can ensure that ambiguous connection conditions do not occur.

About this task

You can create more than one connection to the same data source. The data source is then associated with more than one connection definition. When a Cognos Analytics user queries a data source, the query engine must connect to it. The query engine obtains information about the data source from the content service. However, if the response includes information about two or more connections, the result is an ambiguous connection condition.

When an ambiguous connection condition occurs, the user is prompted to select the connection that the query engine will use.

As administrator, you can prevent ambiguous connection conditions from occurring. This ensures that a user won't be prompted during a query operation. You can achieve this in two ways:

  • by modifying who can use the data source connection
  • by modifying the status of the data source connection
Note: After you modify a data source connection using one of these methods, it can take several minutes for the Dynamic Query server to apply your changes. Applications that use the Compatible Query engine apply your changes immediately.

Example: Modifying user access to a connection

The data source dsone includes the connections connone and conntwo. The user userone runs a report on the data source dsone. While the report is running, userone is prompted to choose which connection they want to use.

To ensure that userone does not encounter this ambiguous connection condition again, you edit the userone's access to the connone connection:

  1. Click Manage > Data server connections.
  2. In the connection list, click connone.
  3. Click the Permissions tab.
  4. Select Override parent permissions.
  5. Click the add icon add icon, and specify access for a group or role to which userone does not belong.
  6. Remove access for roles and groups that include userone by clicking the Remove selected item icon Remove selected item icon.
  7. Click Apply.

The next time userone runs the report, the query engine again requests information about the data source dsone. However, now the response returns only the connection conntwo, as this is the only connection that userone can access.

Example: Modifying a connection's status

The data source dsone includes the connections connone and conntwo. The user usertwo runs a report on the data source dsone. While the report is running, usertwo is prompted to choose which connection they want to use.

To ensure that any user, including usertwo, does not encounter this ambiguous connection condition again, you decide to disable the connone connection:

  1. Click Manage > Data server connections.
  2. In the connection list, click connone.
  3. Click Advanced.
  4. Select the Disable this entry check box.

The next time any user runs the report, the query engine again requests information about the data source dsone. However, now the response returns only the connection conntwo, as this is the only connection that any user can access.