对象关系数据库中的时空索引机制研究

时空数据库是近年来地理信息科学与数据库技术领域研究和应用的热点，其中时空数据模型和时空数据索引技术是时空数据库的关键。为了提高时空数据库查询处理的效率，在基于时间片的连续快照模型基础上，改进了PP-TPR树索引。该索引技术不仅可以处理普通的空间查询（点查询和范围查询），在时间维度上还可以支持单纯时间维度的查询、历史状态查询、预期状态查询以及时空一体化的复杂查询。在实例研究中，采用对象关系数据库PostgreSQL作为时空数据类型和时空数据索引的实现平台，初步验证了上述时空索引技术的有效性和实用性。

On Spatio-Temporal Data Access Methods in ORDBMS

Spatio-temporal data model and spatio-temporal data access methods are the two key technologies in spatio-temporal databases.In this paper,the Snapshot Model was used to represent and store spatio-temporal data.Then a review and comparison of existing spatio-temporal data access methods were given.In order to speed the query processing,an improved PP-TPR tree was adopted basing on the former analysis of various kinds of spatio-temporal indexing techniques.This kind of improved PP-TPR tree supports various kinds of spatio-temporal query including prediction and history query.All these techniques cited above were implemented in the world's most popular open-source ORDBMS,namely PostgreSQL.The experimental results come out to indicate that the research work in this paper is really a good attempt in spatio-temporal data access method fields.