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
PostgreSQL Overview

Checking for missing indexes

Once you are done with the first three steps, it is important to take a look at performance in general. As I kept stating throughout this book, missing indexes are super important to achieve super bad performance. So, whenever you are facing a slow system, is it recommended to check for missing indexes and deploy whatever is needed.

Usually customers ask you to optimize the RAID level, tune the kernel, or some other fancy stuff. In reality, those complicated requests often boil down to a handful of missing indexes. By my judgment, it always makes sense to spend some extra time on just checking whether all desired indexes are there. Checking for missing indexes is neither hard nor time consuming, so it should be done all the time regardless of the kind of performance problem you are facing.

Here is my favorite query to get an impression of where an index might be missing:

SELECT   schemaname...