XML文档顺序的维护

Maintaining Order in an XML Document

为提高查询和更新的效率,XML 文档中的对象必须拥有顺序标识(OID)。本文在 Numbering sheme 的基础上提出了基于模式的顺序维护算法。新算法包括 OID 区间预留算法和 OID 维护算法两部分。在文档初始化时,前者基于模式和统计信息对未来的插入操作进行 OID 区间预留,后者则在前者的基础上将插入操作时的全局调整化解为局部调整。新算法可以有效降低 XML 文档顺序维护的代价。

Sequential order should be maintained in an XML document to improve the efficiency of query and update operations upon it. This paper proposes a Schema-based order maintaining algorithm after Numbering scheme.The new algorithm mainly includes two parts. The first is OID reserving,which implements OID space reservation based on the Schema and statistic information of a sample during initialization. The second one is OID maintaining,which de- grades globe reordering to local reordering based on the first part. The new algorithm reduces maintenance overhead effectively.