◾ Multiple-Query Processing and Optimization Techniques for Multitenant Databases
In the data management eld, multiple-query processing and optimization problem has long historically extensively been investigated, spanning from relational databases, deductive databases, semistructured Extensible Markup Language (XML) databases, to streaming databases. Given a set of database queries, instead of separately processing the queries one at a time, multiple-query optimization (MQO) aims to perform the queries together by taking advantage of common data and common query subexpressions that these queries may have. In this way, redundant data access can be avoided and the overall execution time can be reduced. In this chapter, the aim is to survey two main bodies of research activities in traditional databases and streaming databases. Based on the previous classic models, we discuss some possible extensions in the multitenant database domain.