CHAPTER 15
Subqueries and Domain Aggregate Functions
Often, you'll carry out your analyses in layers, each layer of analysis using or building on the previous layer. This practice of building layers into analytical processes is actually very common. For instance, when you build a query using another query as the data source, you're layering your analysis. When you build a query based on a temporary table created by a makeātable query, you're also layering your analysis.
All these conventional methods of layering analyses have two things in common:
- They all add a step to your analytical processes. Every query that has to be run in order to feed another query, or every temporary table that has to be created in order to advance your analysis, adds yet another task that must be completed before you get your final results.
- They all require the creation of temporary tables...