> [!NOTE] ![[assets/wl_lwlock_notifyqueue.png|256]] > > | | | > | :--- | :--- | > | **Wait Category** | LWLock | > | **Mechanism** | `NotifyQueueLock` | > | **Operations** | [[Operations/Table/SeqScan]] | > | **Resources** | [[Resources/RAM|Memory]], [[Resources/CPU|CPU]] | > > **Message Dispatch Serialization point**. When a session executes `NOTIFY`, the message is appended to a global shared memory queue; when a `LISTEN`ing session checks for updates, it must read from this same queue.