Book Image

Mastering PostgreSQL 11 - Second Edition

By : Hans-Jürgen Schönig
Book Image

Mastering PostgreSQL 11 - Second Edition

By: Hans-Jürgen Schönig

Overview of this book

This second edition of Mastering PostgreSQL 11 helps you build dynamic database solutions for enterprise applications using the latest release of PostgreSQL, which enables database analysts to design both the physical and technical aspects of the system architecture with ease. This book begins with an introduction to the newly released features in PostgreSQL 11 to help you build efficient and fault-tolerant PostgreSQL applications. You’ll examine all of the advanced aspects of PostgreSQL in detail, including logical replication, database clusters, performance tuning, monitoring, and user management. You will also work with the PostgreSQL optimizer, configuring PostgreSQL for high speed, and see how to move from Oracle to PostgreSQL. As you progress through the chapters, you will cover transactions, locking, indexes, and optimizing queries to improve performance. Additionally, you’ll learn to manage network security and explore backups and replications, while understanding the useful extensions of PostgreSQL so that you can optimize the speed and performance of large databases. By the end of this book, you will be able to use your database to its utmost capacity by implementing advanced administrative tasks with ease.
Table of Contents (15 chapters)
Free Chapter
1
PostgreSQL Overview

Introducing operator classes

So far, the goal has been to figure out what to index and whether to blindly apply an index on this column or on a group of columns. There is one assumption, however, that we have silently accepted to make this work. Up until now, we have worked on the assumption that the order in which the data has to be sorted is a somewhat fixed constant. In reality, this assumption might not hold true. Sure, numbers will always be in the same order, but other kinds of data will most likely not have a predefined, fixed sort order.

To prove my point, I have compiled a real-world example. Take a look at the following two records:

1118 09 08 78 
2345 01 05 77 

My question now is, are these two rows ordered properly? They might be, because one comes before another. However, this is wrong because these two rows do have some hidden semantics. What you can see here are...