Relationships for Dynamic Data Types in RSQL
Relationships for Dynamic Data Types in RSQL
复制标题
RSQL 中动态数据类型的关系
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
Wolfgang Lehner
中科院分区：
文献类型：
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作者：
Tobias Jäkel;Thomas Kühn;Stefan Hinkel;H. Voigt;Wolfgang Lehner
目前，信息系统的概念模型和数据库管理系统（DBMS）中的实现之间存在不匹配。大多数概念建模语言都将它们的概念实体与关系联系起来，但是关系数据库管理系统仅仅依赖于关系的概念来对实体和关系进行建模。更糟糕的是，真实的世界对象并不像这些建模语言中所假设的那样是静态的，而是随着时间而变化。因此，建模语言也得到了丰富，可以对这些场景进行建模。然而，将这些模型映射到关系数据库需要使用对象关系映射引擎，这反过来又对DBMS隐藏了概念模型的语义。因此，传统的关系数据库系统不能直接确保特定的一致性约束，从而失去了它们作为高度分布式信息系统的单点真理的意义。为了克服这些问题，我们提出了RSQL，一个数据模型和查询语言，在DBMS中引入基于角色的数据结构。尽管RSQL能够处理复杂对象，但它不支持这些对象之间的关系。因此，这项工作通过增强数据模型和扩展其查询语言来向RSQL添加关系。因此，这种扩展允许在DBMS中直接表示具有复杂对象和关系的概念模型。因此，关系可以直接在查询中处理，DBMS自动确保关系的一致性约束以及基数。总而言之，配备扩展RSQL的数据库管理系统适合存储和查询概念模型，从而重新获得其作为高度分布式信息系统的单一事实点的应有地位。
Currently, there is a mismatch between the conceptual model of an information system and its implementation in a database management system (DBMS). Most of the conceptual modeling languages relate their conceptual entities with relationships, but relational database management systems solely rely on the notion of relations to model both, entities and relationships. To make things worse, real world objects are not static as assumed in such modeling languages, but change over time. Thus, modeling languages were enriched to model those scenarios, as well. However, mapping these models onto relational databases requires the use of object-relational mapping engines, which in turn hide the semantics of the conceptual model from the DBMS. Consequently, traditional relational database systems cannot directly ensure specific consistency constraints and thus lose their meaning as single point of truth for highly distributed information systems. To overcome these issues we have proposed RSQL, a data model and query language introducing role-based data structures in DBMSs. Despite the fact that RSQL is able to handle complex objects, it does not support relationships between those objects. Therefore, this work adds relationships to RSQL by augmenting the data model and extending its query language. As a result, this extension allows for the direct representation of conceptual models with complex objects and relationships in the DBMS. Thus, relationships can be directly addressed in queries and the DBMS automatically ensures relationship consistency constraints as well as cardinality. In sum, a DBMS equipped with the extended RSQL is apt for storing and querying conceptual models and thus regains its rightful position as the single point of truth for highly distributed information systems.