Book Image

PostgreSQL 10 Administration Cookbook - Fourth Edition

By : Simon Riggs, Gianni Ciolli
Book Image

PostgreSQL 10 Administration Cookbook - Fourth Edition

By: Simon Riggs, Gianni Ciolli

Overview of this book

PostgreSQL is a powerful, open source database management system with an enviable reputation for high performance and stability. With many new features in its arsenal, PostgreSQL 10 allows users to scale up their PostgreSQL infrastructure. This book takes a step-by-step, recipe-based approach to effective PostgreSQL administration. Throughout this book, you will be introduced to these new features such as logical replication, native table partitioning, additional query parallelism, and much more. You will learn how to tackle a variety of problems that are basically the pain points for any database administrator - from creating tables to managing views, from improving performance to securing your database. More importantly, the book pays special attention to topics such as monitoring roles, backup, and recovery of your PostgreSQL 10 database, ensuring high availability, concurrency, and replication. By the end of this book, you will know everything you need to know to be the go-to PostgreSQL expert in your organization.
Table of Contents (14 chapters)

Discovering why a query is not using an index

This recipe explains what to do if you think your query should use an index, yet it does not.

There could be several reasons for this, but most often, the reason is that the optimizer believes that, based on the available distribution statistics, it is cheaper and faster to use a query plan that does not use that specific index.

Getting ready

First, check that your index exists, and ensure that the table has been analyzed. If there is any doubt, rerun it to be sure:

postgres=# ANALYZE;
ANALYZE

How to do it...

Force index usage...