Advanced Queuing is the message broker built into the database. Messages live in queue tables and are enqueued and dequeued with DBMS_AQ inside ordinary database transactions, so a business update and its outgoing message commit or roll back together. It supports point-to-point and publish-subscribe queues, rule-based subscribers, persistent and buffered messages, propagation between queues on different databases, asynchronous notifications, and a Java Message Service interface.

Migrations care because the transactional coupling between data and messages is exactly what external brokers lack. Moving to Azure Service Bus or Storage queues typically requires an outbox pattern to preserve atomicity, and PL/SQL consumers become functions or services. Queue tables, subscriber rules and propagation schedules are configuration that assessment tools rarely surface.

Oracle's 19c Upgrade Guide states, in the Streams desupport notice, that Advanced Queuing is not deprecated and is fully supported. The 21c guide deprecates sharded queues in favor of Transactional Event Queues, which are the evolution of the same feature.

Oracle Advanced Queuing, born before 11.2, spent its life providing in-database queues and transactional enqueueing and dequeueing alongside table changes. It served point-to-point and publish-subscribe messaging without leaving the database transaction.

Its Azure departure was sealed by Azure SQL Database, which has neither Service Broker nor another in-database queue. External Service Bus transactions cannot include database DML, leaving an outbox table or idempotent consumers to settle the estate.

It is survived by Azure SQL Database, not at all; Azure SQL Managed Instance, partly; and Azure Service Bus, partly. Managed Instance offers transactional Service Broker with restricted routing, while Service Bus preserves many messaging patterns but not AQ’s shared database transaction.