Extending the View Updatability of Relational Databases from Set Semantics to Bag Semantics and its Implementation on PostgreSQL
Extending the View Updatability of Relational Databases from Set Semantics to Bag Semantics and its Implementation on PostgreSQL
复制标题
将关系数据库视图更新性从集合语义扩展到包语义及其在 PostgreSQL 上的实现
DOI：
10.1145/3164541.3164584
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
and T. Ishii
中科院分区：
文献类型：
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作者：
Y. Masunaga;Y. Nagata;and T. Ishii
从理论和实践的角度来看，视图支持都是关系数据库最吸引人的特性之一。然而，由于视图并不是存储在数据库中的基本关系，而仅仅是对数据库发出的查询的定义，因此视图的可更新性带来了一个称为视图更新问题的难题。为了解决这一问题，人们进行了许多理论研究，包括句法、语义、互动和基于意图的方法，其中基于意图的方法是最有前途的。在实践中，SQL-92标准化了可更新视图的充要条件，但其可更新性是有限的。尽管可更新视图的新标准在SQL：1999中得到了标准化，但它的实现似乎很困难。为了使关系数据库用户受益，我们的目标是为关系数据库管理系统实现基于意图的方法。然而，我们在这样做的过程中面临两个问题。因此，在本研究中，我们提出了针对这些问题的积极解决方案。首先，由于理论工作都是基于集合语义学和关于袋子语义的SQL标准，基于意图的方法能否扩展到袋子语义还有待研究。其次，该方法应该在国际上流行的开源关系数据库管理系统PostgreSQL上实现。
View support is one of the most attractive features of relational databases from both theoretical and practical points of view. However, as views are not base relations stored in a database but merely definitions of queries issued to a database, the updatability of views poses a difficult dilemma known as the view update problem. To resolve the problem, many theoretical investigations, namely, the syntactic, semantic, interactive, and intention-based approaches were conducted, with the intention-based approach being the most promising. In practice, SQL-92 standardized a necessary and sufficient condition for updatable views, but its updatability is limited. Although new criteria for updatable views were standardized in SQL:1999, its implementation seemed to be hard. To benefit relational database users, we aimed to implement the intention-based approach for a relational database management system. However, we faced two issues in doing so. Therefore, in this study, we present the positive solutions to these problems. First, as theoretical works are based on set semantics and SQL standards on bag semantics, whether the intention-based approach can be extended to bag semantics or not should be investigated. Second, the approach should be implemented on PostgreSQL, which is the prevalent open source relational database management system in the world.