# 6.25. ODPI-C Enumeration dpiSubscrNamespace

This enumeration identifies the namespaces supported by subscriptions.

Value | Description
--- | ---
DPI_SUBSCR_NAMESPACE_AQ | Identifies the namespace used for receiving notifications when messages are available to be dequeued in advanced queueing (AQ).
DPI_SUBSCR_NAMESPACE_DBCHANGE | Identifies the namespace used for receiving notifications for database object changes and query changes (CQN).