Book Image

PostgreSQL 10 Administration Cookbook - Fourth Edition

Book Image

PostgreSQL 10 Administration Cookbook - Fourth Edition

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)

Finding a unique key for a set of data

Sometimes, it can be difficult to find a unique set of key columns that describe the data.

Getting ready

Let's start with a small table, where the answer is fairly obvious:

postgres=# select * from ord;

We assume that the output is as follows:

orderid  | customerid |  amt  
---------+------------+--------
10677 | 2 | 5.50
5019 | 3 | 277.44
9748 | 3 | 77.17
(3 rows)

How to do it...

First of all, there's no need to do this through a brute-force approach. Checking all the permutations of...