Book Image

Learning PostgreSQL 11 - Third Edition

By : Salahaldin Juba, Andrey Volkov
Book Image

Learning PostgreSQL 11 - Third Edition

By: Salahaldin Juba, Andrey Volkov

Overview of this book

PostgreSQL is one of the most popular open source database management systems in the world, and it supports advanced features included in SQL standards. This book will familiarize you with the latest features in PostgreSQL 11, and get you up and running with building efficient PostgreSQL database solutions from scratch. Learning PostgreSQL, 11 begins by covering the concepts of relational databases and their core principles. You’ll explore the Data Definition Language (DDL) and commonly used DDL commands supported by ANSI SQL. You’ll also learn how to create tables, define integrity constraints, build indexes, and set up views and other schema objects. As you advance, you’ll come to understand Data Manipulation Language (DML) and server-side programming capabilities using PL/pgSQL, giving you a robust background to develop, tune, test, and troubleshoot your database application. The book will guide you in exploring NoSQL capabilities and connecting to your database to manipulate data objects. You’ll get to grips with using data warehousing in analytical solutions and reports, and scaling the database for high availability and performance. By the end of this book, you’ll have gained a thorough understanding of PostgreSQL 11 and developed the necessary skills to build efficient database solutions.
Table of Contents (18 chapters)

Tuning performance for read

PostgreSQL provides the means to figure out why a certain query is slow. Behind the scenes, PostgreSQL analyzes tables, collects statistics from them, and builds histograms using auto-vacuuming. Auto-vacuuming, in general, is used to recover disk space, update table statistics, and perform other maintenance tasks, such as preventing transaction-ID wraparound. Table statistics allow PostgreSQL to pick up an execution plan with the least cost. The least cost is calculated by taking into account the I/O and, naturally, the CPU cost. Also, PostgreSQL enables users to see the generated execution plan by providing the EXPLAIN command.

For beginners, it's extremely useful to write the same query in different ways and compare the results. For example, in some cases, the NOT IN construct can be converted to LEFT JOIN or NOT EXIST. Also, the IN construct...