Creating Database Session-Based Application Contexts

A database session-based application context is a named object that stores the user’s session information.

About Creating Database Session-Based Application Contexts

A database user session (UGA) stores session-based application context, using a user-created namespace.

Each application context must have a unique attribute and belong to a namespace. That is, context names must be unique within the database, not just within a schema.

You must have the CREATE ANY CONTEXT system privilege to create an application context, and the DROP ANY CONTEXT privilege to use the DROP CONTEXT statement if you want to drop the application context.

The ownership of the application context is as follows: Even though a user who has been granted the CREATE ANY CONTEXT and DROP ANY CONTEXT privileges can create and drop the application context, it is owned by the SYS schema. Oracle Database associates the context with the schema account that created it, but if you drop this user, the context still exists in the SYS schema. As user SYS, you can drop the application context.

You can find the names of existing application contexts by running the following query:

SELECT OBJECT_NAME FROM DBA_OBJECTS WHERE OBJECT_TYPE ='CONTEXT';

Creating a Database Session-Based Application Context

The CREATE CONTEXT SQL statement can be used to create a database session-based application context.

When you create a database session-based application context, you must create a namespace for the application context and then associate it with a PL/SQL package that manages the name-value pair that holds the session information of the user. At the time that you create the context, the PL/SQL package does not need to exist, but it must exist at run time.

CREATE CONTEXT empno_ctx USING set_empno_ctx_pkg CONTAINER = CURRENT;

In this example:

Notice that when you create the context, you do not set its name-value attributes in the CREATE CONTEXT statement. Instead, you set these in the PL/SQL package that you associate with the application context. The reason you must do this is to prevent a malicious user from changing the context attributes without proper attribute validation. Ensure that this package is in the same container as the application context. For example, if you created the application context in a PDB, then the PL/SQL package must reside in that PDB. Note: You cannot create a context called CLIENTCONTEXT. This word is reserved for use with client session-based application contexts. See Using Client Session-Based Application Contexts for more information about this type of application context.

Database Session-Based Application Contexts for Multiple Applications

For each application, you can create an application context that has its own attributes.

Suppose, for example, you have three applications: General Ledger, Order Entry, and Human Resources.

You can specify different attributes for each application:

The data the attributes access is stored in the tables behind the applications. For example, the order entry application uses a table called OE.CUSTOMERS, which contains the CUSTOMER_NUMBER column, which provides data for the CUSTOMER_NUMBER attribute. In each case, you can adapt the application context to your precise security needs.