Subqueries and Domain Aggregate Functions
Michael Alexander, Dick Kusleika · 2018
Subqueries and domain aggregate functions allow users to build layers into their analyses within one query, eliminating the need for tables or transitory queries. Subqueries are select queries that are nested within other queries. The primary purpose of a subquery is to enable the users to use the results of one query within the execution of another query. Even though using subqueries comes with a performance hit, it may be an acceptable trade for streamlined procedures and optimized analytical processes. This chapter presents few rules and restrictions that the users must be aware of when using subqueries. Domain aggregate functions enable them to extract and aggregate statistical information from an entire data set. There are 12 different domain aggregate functions in Access, each performing a different operation. The chapter reviews the purpose and utility of each function. The domain aggregate functions aren't very efficient when it comes to performing large-scale analyses and crunching very large data sets.