Associates up to 128 bytes of binary information with the current session or connection.
Multiple active result sets (MARS) enables applications to run multiple batches, or requests, at the same time on the same connection.
When one of the batches on a MARS connection runs SET CONTEXT_INFO, the new context value is returned by the CONTEXT_INFO function when it is run in the same batch as the SET statement.
The new value is not returned by the CONTEXT_INFO function run in one or more of the other batches on the connection, unless they started after the batch that ran the SET statement completed.