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

Optimizer settings for cached data

In PostgreSQL, by default, some configuration settings are configured to deal with disk I/O; that is, cost related to perform a sequential and random disk scans.

The following are the default values for these parameters:

postgres=# SHOW seq_page_cost ;


To perform a single tuple fetch from the disk, the required cost is 1.

postgres=# SHOW random_page_cost ;

To perform a single tuple fetch by referring its index, the required cost is 4.

If all our table's data or the complete database fits in the existing RAM size, then we can lower these values to as minimum as possible, since we don't need to perform any disk I/O operations.

Let's see the plan before setting these parameters, and then we will see the plan cost after lowering them.

Set the parameters with default settings as follows:

postgres=# SET random_page_cost to default ;
postgres=# SET seq_page_cost to default ;