Joe Celko's SQL for Smarties, 5th Edition

Chapter 31

Partitioning and Aggregating Data in Queries

Abstract

This section is concerned with how to break the data in SQL into meaningful subsets that can then be presented to the user or passed along for further reduction. This is not the same as physical partitioning which moves data to slower storage administrative reasons.

Keywords

Subsets

Partition

Covering

Ranges

Soundex function

NTILE()

This chapter is concerned with how to break the data in SQL into meaningful subsets that can then be presented to the user or passed along for further reduction.

31.1 Coverings and Partitions

We need to define some basic set operations. A covering is a collection of subsets, drawn from a set, whose union is the original set. A partition is a covering ...