Book Image

Mastering PostgreSQL 10

Book Image

Mastering PostgreSQL 10

Overview of this book

PostgreSQL is an open source database used for handling large datasets (big data) and as a JSON document database. This book highlights the newly introduced features in PostgreSQL 10, and shows you how you can build better PostgreSQL applications, and administer your PostgreSQL database more efficiently. We begin by explaining advanced database design concepts in PostgreSQL 10, along with indexing and query optimization. You will also see how to work with event triggers and perform concurrent transactions and table partitioning, along with exploring SQL and server tuning. We will walk you through implementing advanced administrative tasks such as server maintenance and monitoring, replication, recovery, high availability, and much more. You will understand common and not-so-common troubleshooting problems and how you can overcome them. By the end of this book, you will have an expert-level command of advanced database functionalities and will be able to implement advanced administrative tasks with PostgreSQL 10.
Table of Contents (15 chapters)

Introducing operator classes

So far, the goal was to figure out what to index and 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 those 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 see here are two Austrian social...