Book Image

PostgreSQL 14 Administration Cookbook

By : Simon Riggs, Gianni Ciolli
5 (1)
Book Image

PostgreSQL 14 Administration Cookbook

5 (1)
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 14 allows you to scale up your PostgreSQL infrastructure. With this book, you'll take a step-by-step, recipe-based approach to effective PostgreSQL administration. This book will get you up and running with all the latest features of PostgreSQL 14 while helping you explore the entire database ecosystem. You’ll learn how to tackle a variety of problems and pain points you may face as a database administrator such as creating tables, managing views, improving performance, and securing your database. As you make progress, the book will draw attention to important topics such as monitoring roles, validating backups, regular maintenance, and recovery of your PostgreSQL 14 database. This will help you understand roles, ensuring high availability, concurrency, and replication. Along with updated recipes, this book touches upon important areas like using generated columns, TOAST compression, PostgreSQL on the cloud, and much more. By the end of this PostgreSQL book, you’ll have gained the knowledge you need to manage your PostgreSQL 14 database efficiently, both in the cloud and on-premise.
Table of Contents (14 chapters)

Carefully removing unwanted indexes

Carefully removing? Do you mean pressing Enter gently after typing DROP INDEX? Err, no!

The reasoning is that it takes a long time to build an index and a short time to drop it.

What we want is a way of removing an index so that if we discover that removing it was a mistake, we can put the index back again quickly.

Getting ready

The following query will list all invalid indexes, if any:

SELECT ir.relname AS indexname 
, it.relname AS tablename 
, n.nspname AS schemaname 
FROM pg_index i 
JOIN pg_class ir ON ir.oid = i.indexrelid 
JOIN pg_class it ON it.oid = i.indrelid 
JOIN pg_namespace n ON n.oid = it.relnamespace 
WHERE NOT i.indisvalid; 

Take note of these indexes so that you can tell whether a given index is invalid later because we marked it as invalid during this recipe, in which case it can safely be marked as valid, or because it was already invalid for other reasons.

How to do it…