Book Image

PostgreSQL Development Essentials

By : Manpreet Kaur, Baji Shaik
Book Image

PostgreSQL Development Essentials

By: Manpreet Kaur, Baji Shaik

Overview of this book

PostgreSQL is the most advanced open source database in the world. It is easy to install, configure, and maintain by following the documentation; however, it’s difficult to develop applications using programming languages and design databases accordingly. This book is what you need to get the most out of PostgreSQL You will begin with advanced SQL topics such as views, materialized views, and cursors, and learn about performing data type conversions. You will then perform trigger operations and use trigger functions in PostgreSQL. Next we walk through data modeling, normalization concepts, and the effect of transactions and locking on the database. The next half of the book covers the types of indexes, constrains, and the concepts of table partitioning, as well as the different mechanisms and approaches available to write efficient queries or code. Later, we explore PostgreSQL Extensions and Large Object Support in PostgreSQL. Finally, you will perform database operations in PostgreSQL using PHP and Java. By the end of this book, you will have mastered all the aspects of PostgreSQL development. You will be able to build efficient enterprise-grade applications with PostgreSQL by making use of these concepts
Table of Contents (17 chapters)
PostgreSQL Development Essentials
About the Authors
About the Reviewers

Explain Plan

Postgres has a great ability to show you how it will actually execute a query under the covers. This is known as an execution plan, and it is exposed by the explain command. Understanding this tells you how you can optimize your database with indexes to improve performance.

Every query within Postgres has an execution plan when executed. There are three ways to run explain to expose this to you:

  • The generic form (only shows what is likely to happen)

  • The Analyze form (which actually runs the query, and outputs what does happen)

  • The Verbose form (verbose information)

Most commonly, explain is run on the SELECT statements. However, you can also use it on the following:






Generating and reading the Explain Plan

For each step in the execution plan, EXPLAIN prints the following information:

  • The type of operation required.

  • The estimated cost of execution.

  • If you specified EXPLAIN ANALYZE, it gives the actual cost of execution. If you omit the ANALYZE keyword...