OPTIMIZATION OF "ASSOCIATE-SELECT" COMPOUND OPERATION IN OBJECT-ORIENTED; DATABASE SYSTEMS
面向对象数据库中“联系-选择”复合操作的优化

Associate-Select" compound operation, which is similar in functionality tojoin operation of multi-nested relations in nested relational databases, is a key issue ofquery optimization in object-oriented database systems. This paper proves that the opti-mum solution for treelike "Associate-Select" queries with some restrictions can be obtainedwith polynomial complexity, then presents some algorithrns to deal with the situationwhen birelationship exists in complex objects(for example by defining inverse attribute etal. ). A simulation experiment is performed to demonstrate the steadiness and effectivenes s of the algorithms proposed in the paper.