Book Image

PostgreSQL 11 Administration Cookbook

By : Simon Riggs, Gianni Ciolli, Sudheer Kumar Meesala
Book Image

PostgreSQL 11 Administration Cookbook

By: Simon Riggs, Gianni Ciolli, Sudheer Kumar Meesala

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 11 allows you to scale up your PostgreSQL infrastructure. This book takes a step-by-step, recipe-based approach to effective PostgreSQL administration. The book will introduce you to new features such as logical replication, native table partitioning, additional query parallelism, and much more to help you to understand and control, crash recovery and plan backups. You will learn how to tackle a variety of problems and pain points for any database administrator such as creating tables, managing views, improving performance, and securing your database. As you make steady progress, the book will draw attention to important topics such as monitoring roles, backup, and recovery of your PostgreSQL 11 database to help you understand roles and produce a summary of log files, ensuring high availability, concurrency, and replication. By the end of this book, you will have the necessary knowledge to manage your PostgreSQL 11 database efficiently.
Table of Contents (19 chapters)
Title Page
Copyright and Credits
About Packt

Checking which queries are running

In this section, we will show you how to check which query is currently running.

Getting ready

You have to make sure that you are logged in as a superuser or as the same database user you want to check out. Also, ensure that the track_activities = on parameter is set (which it normally should be, being the default setting). If not, check the Updating the parameter file recipe in Chapter 3, Configuration.

How to do it…

To see which connected users are running at this moment, just run the following code:

SELECT datname, usename, state, query
       FROM pg_stat_activity;

On systems with a lot of users, you may notice that the majority of backends have state set to idle. This denotes that no query is actually running, and PostgreSQL is waiting for new commands from the user. The query field shows the statement that was last executed by that particular backend.

If, on the other hand, you are interested in active queries only, limit your selection to those records...