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)

Changing the data type of a column

Thankfully, changing column data types is not an everyday task, but when we need to do it, we must understand the behavior to ensure we can execute the change without any problem.

Getting ready

Let's start with a simple example of a table, with just one row, as follows:

( name       TEXT
, dob        INTEGER);
INSERT INTO birthday VALUES ('simon', 690926);
postgres=# select * from birthday;

This gives us the following output:

 name  |  dob  
 simon | 690926
(1 row)

How to do it…

Let's say we want to change the dob column to another data type. Let's try this with a simple example first, as follows:

postgres=# ALTER TABLE birthday
postgres-# ALTER COLUMN dob SET DATA TYPE text;

This works fine. Let's just change...