Book Image

Mastering PostgreSQL 9.6

By : Hans-Jürgen Schönig
Book Image

Mastering PostgreSQL 9.6

By: Hans-Jürgen Schönig

Overview of this book

PostgreSQL is an open source database used for handling large datasets (Big Data) and as a JSON document database. It also has applications in the software and web domains. This book will enable you to build better PostgreSQL applications and administer databases more efficiently. We begin by explaining the advanced database design concepts in PostgreSQL 9.6, 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 and high availability, and much more. You will understand the 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 the advanced database functionalities and will be able to implement advanced administrative tasks with PostgreSQL.
Table of Contents (14 chapters)
Free Chapter
1
PostgreSQL Overview

Understanding execution plans

After digging into some important optimizations implemented into PostgreSQL, I want to shift your attention a bit more to execution plans. You have already seen some plans in this book. However, in order to make full use of plans, it is important to develop a systematic approach to reading this information. Reading plans systematically is exactly within the scope of this section.

Approaching plans systematically

The first thing you have to know is that an EXPLAIN clause can do quite a lot for you and I would highly recommend to make full use of those features.

As many readers might already know, an EXPLAIN ANALYZE clause will execute the query and return the plan including real runtime information. Here is an example:

test=# EXPLAIN...