Discoverer Connections

Oracle Discoverer requires its own connection information, as it is possible, depending on privileges granted in the database, for a user to connect to different End- User Layers (EULs). A Discoverer connection can be created in one of two ways:

• By having an administrator create a Discoverer connection via the Oracle Enterprise Manager web site

• By configuring Discoverer Server so that users are allowed to create their own connections (this feature can be disabled)

Creating a Discoverer Connection in the Enterprise Manager Web Site

This is the preferred way to set up connections and the way most administrators will configure their systems. In the Enterprise Manager Web Application Server Control web site for your middle tier , select the Discoverer component. Select Public Connections. Click Create Connections. You ll be presented with a page similar to Figure 5-6.

Figure 5-6: The Create Public Connection screen for Discoverer

On this page, you ll name your connection, select the End-User Layer you wish to connect to, and enter the username/password/connection string information. Asterisks denote required fields, and you ll notice that there is no asterisk next to the Password field under User Account Details ”this allows the administrator to create connections that prompt a user for a password before connecting to the database.

Tip  

The hint on this page states that the End-User Layer is case-sensitive, but this can be misleading. I used the following code to create a user named disco that was going to hold my End-User Layer tables and views:

 SQL> create user disco identified by disco default tablespace disco; User created. 

Although it looks as if the username is in lowercase, it s stored in the data dictionary as uppercase. Attempting to access it in Discoverer Viewer with an End-User Layer entered with lowercase letters (or anything, for that matter, not in all CAPS) will result in a page similar to Figure 5-7.

Figure 5-7: An error when trying to access an EUL in lowercase

Allowing Users to Create Their Own Discoverer Connections

If we return to the Discoverer configuration page on the Enterprise Manager Web site, you ll notice that in the middle of the page, there is a check box next to a line that says Allow users to define and use their own private connections in Discoverer Plus and Discoverer Viewer. By default, this check box is selected, allowing end users to create their own Discoverer connections. This is generally a bad idea, as it is possible for an end user to connect to a wrong database. It also further introduces security risks by letting end users know username/password/connection string information, allowing knowledgeable users direct connections to your database with ( potentially ) malicious tools like SQL*Plus. It s a good idea to disable this feature by deselecting this option, but if you determine that this functionality is worth the risks, leave the default. Users will see a Create Connection button on the top right part of the screen (as in Figure 5-10). If this feature is disabled, the button will not appear. Any connections created using this method are valid for as long as the browser is open .