公开(公告)号：US06405191B1

公开(公告)日：2002-06-11

申请号：US09359170

申请日：1999-07-21

申请人： Neerja Bhatt ,  Dieter Gawlick ,  Ekrem Soylemez ,  Rahim Yaseem

发明人： Neerja Bhatt ,  Dieter Gawlick ,  Ekrem Soylemez ,  Rahim Yaseem

IPC分类号： G06F1730

CPC分类号： G06F17/3051 ,  G06F17/30516 ,  Y10S707/954 ,  Y10S707/99933 ,  Y10S707/99934 ,  Y10S707/99935

摘要： A method and apparatus are provided for implementing a content based publish-and-subscribe system in a relational database system. A subscriber may request for messages by using a query language supported by the database server. The queries are then used as subscription rules for determining whether an incoming message is to be sent to the subscriber. Evaluation of incoming messages against subscription rules involves a two-tier process. The first tier involves filtering out all the subscription rules that could not possibly apply to the incoming message. The second tier involves further evaluation of the incoming message, if needed, to determine which subscribers are to receive the incoming message. In another aspect of the embodiment, in cases where the publisher is the relational database system itself, queries that request for messages are not stored as subscription rules because publication of the messages is implicit.

摘要翻译： 提供了一种用于在关系数据库系统中实现基于内容的发布和订阅系统的方法和装置。 用户可以通过使用数据库服务器支持的查询语言来请求消息。 然后，查询用作订阅规则，用于确定是否要向订户发送传入消息。 根据订阅规则评估传入消息涉及两层过程。 第一层涉及过滤掉不可能应用于传入邮件的所有订阅规则。 第二层涉及进一步评估传入消息，如果需要，确定哪些订户将接收传入消息。 在该实施例的另一方面，在发布者是关系数据库系统本身的情况下，请求消息的查询不被存储为订阅规则，因为消息的发布是隐式的。