多媒体对象查询语言及其查询处理

Multimedia Object Query Language and Its Query Processing

文章研究了多媒体数据库的查询需求，提出结构化的多媒体对象查询语言ＭＯＱＬ（ｍ ｕｌｔｉ－ｍ ｅ－ｄｉａ ｏｂｊｅｃｔｑｕｅｒｙ ｌａｎｇｕａｇｅ）．它能够支持基于类型、结构特征、同步关系、时态关系和内容信息的多媒体查询．以ＤＢ２数据库为存储机制，定义了一组代数算子和变换规则，利用它们可以将用户定义的ＭＯＱＬ查询变换为代数表达式，进行代数优化，并将代数查询表达式转换为能够在ＤＢ２数据库上运行的ＤＢ２ＳＱＬ和Ｃ＋ ＋

In this paper, the authors study the query requirements of multimedia database and propose a structured multimedia object query language (MOQL). The language can support queries based on type, structure, synchronous relations, temporal relations, and contents of multimedia data. Taking the DB2 relational database system as a storage mechanism, they define a set of algebraic operators and some transformation rules, by which the MOQL queries defined by the users can be transformed into a set of algebraic formula and optimized. Finally, the algebraic formula can be transformed into execution plan in DB2SQL and C++ procedures, which can be run on DB2 system.