Point-Based Temporal Extensions of SQL and Their Efficient Implementation
Point-Based Temporal Extensions of SQL and Their Efficient Implementation
复制标题
SQL 基于点的时态扩展及其高效实现
DOI：
--
复制
发表时间：
1997
期刊：
影响因子：
--
通讯作者：
David Toman
中科院分区：
文献类型：
--
作者：
David Toman
本章介绍了一种新的SQL时态扩展方法。与目前大多数建议相比，我们使用单个时间点作为时间的引用，同时仍然实现高效的查询评估。SQL/TP是SQL/92语法的自然扩展：它增加了一个新的数据类型，表示一个线性有序的时间范围。新语言的语义以预期的方式扩展了标准SQL：新数据类型的行为与现有类型相同。我们还消除或修复了许多与在基于区间的语言中定义精确语义有关的问题。此外，我们提供了一个高效的查询评估过程的基础上编译技术，SQL/TP查询SQL/92。因此，现有的现成的数据库系统可以用作管理时态数据的后端。
This chapter introduces a new approach to temporal extensions of SQL. In contrast with most of the current proposals we use single time points as references to time, while still achieving efficient query evaluation. The proposed language, SQL/TP, naturally extends the syntax of SQL/92: it adds a single new data type that represents a linearly ordered universe of time instants. The semantics of the new language extends the standard SQL in the expected way: the new data type behaves identically to the existing types. We also eliminate or fix many of the problems connected with defining a precise semantics in interval-based languages. In addition we provide an efficient query evaluation procedure based on a compilation technique that translates SQL/TP queries to SQL/92. Therefore existing off-shelf database systems can be used as back-ends for managing temporal data.