| 摘要: |
| 归纳了ORDBMS(object-relationaldatabasemanagementsystem)主动性规则的一般描述形式,对规则各种语义、规则继承、规则操作、多规则触发以及规则的级联触发进行了全面的探讨.提出并实现了一种适用于ANGEL系统的简化E-C-A(event-condition-action)模型.该模型提供了对"更新/更新”、"查询/更新”、"更新/查询”和"查询/查询”这4类规则的支持、对C-A分离耦合模式以及对冲突执行触发器的优先级定义手段,并通过在触发约束表示中将NEW与OLD扩展为一种路径量词而提供了对集合约束的表示和实施能力.另外,还讨论了该模型中基于事务的规则行为分析方法. |
| 关键词: ORDBMS(object-relational database management system) E-C-A(event-condition-action)模型 规则 触发器 |
| DOI： |
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| 基金项目:国家自然科学基金资助项目(60073055);国家重点基础研究发展规划973资助项目(G1999032705) |
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| Research and Implementation of the Active Rules in ORDBMS |
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LI Hong yan,LI Zhan huai,TANG Shi wei
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| Abstract: |
| In this paper, the formalized description of active rules in ORDBMS (object-relational database management system) is presented. The semantics of rule components, rule inheritance, rule operations, multiple rule triggering and rule cascade triggering is fully discussed. And a simplified E-C-A (event-condition-action) model called S E-C-A model suited to ANGEL system is achieved. Four types of rules (update-update rules, update-query rules, query-update rules and query-query rules), C-A coupling mode and priority definition of conflicting triggers are supported in S E-C-A. The capabilities of express and actualize set constraints are gained by extending NEW and OLD to a kind of path quantifier in expression forms of trigger constraint. And the analytic methods of rule behaviors based on transaction are also presented. |
| Key words: ORDBMS （object relational database management system） E C A model rule trigger |
