Importance

Loading Importance Indicators...

Abstract

An advanced message queuing system is integrated into a database system. A queue is an ordered list of messages. Messages are requests for processing by an application. Messages are database objects and can represent events or data. Messages comprise user data and control information such as a queue name. Each queue is part of a table in a relational database. A queue table holds a set of queues. Dictionary tables store configuration information describing queues and queue tables. Messages are entered into a queue by instructing the database system using an enqueuing command attached to a message and control information. The control information describes how to order, schedule, and execute the message, and can include a result queue name into which a result message is written after execution. The system responds to a dequeuing command by delivering a copy of a message from the queue. A user can define message order within a queue, message delay factors, and exception processing. Messages may be retained in their queues after delivery and can be preserved, queried, documented, correlated, reviewed and tracked, alone or in a set comprising a transaction, regardless of message state or execution state. The system can be used to develop large-scale, message-oriented distributed applications. Existing development tools for database applications can also be used to develop queuing applications. Administrative functions to create, delete, and specify access control for queues are provided. The system provides transactional integrity; a single transaction applies to both the database and the queue. A single transaction log is maintained.

Loading the Abstract Image...

First Claim