Book Image

Learn PostgreSQL - Second Edition

By : Luca Ferrari, Enrico Pirozzi
1 (2)
Book Image

Learn PostgreSQL - Second Edition

1 (2)
By: Luca Ferrari, Enrico Pirozzi

Overview of this book

The latest edition of this PostgreSQL book will help you to start using PostgreSQL from absolute scratch, helping you to quickly understand the internal workings of the database. With a structured approach and practical examples, go on a journey that covers the basics, from SQL statements and how to run server-side programs, to configuring, managing, securing, and optimizing database performance. This new edition will not only help you get to grips with all the recent changes within the PostgreSQL ecosystem but will also dig deeper into concepts like partitioning and replication with a fresh set of examples. The book is also equipped with Docker images for each chapter which makes the learning experience faster and easier. Starting with the absolute basics of databases, the book sails through to advanced concepts like window functions, logging, auditing, extending the database, configuration, partitioning, and replication. It will also help you seamlessly migrate your existing database system to PostgreSQL and contains a dedicated chapter on disaster recovery. Each chapter ends with practice questions to test your learning at regular intervals. By the end of this book, you will be able to install, configure, manage, and develop applications against a PostgreSQL database.
Table of Contents (22 chapters)
20
Other Books You May Enjoy
21
Index

The default partition

In this section, we will see what happens if we insert data into a partitioned table where the child partition does not exist, and how to resolve the inconvenience this causes. To simulate this problem, suppose we want to insert a date corresponding to 2023-05-01 on the table called part_tags. We would get this result:

forumdb=> insert into part_tags (tag,ins_date,level) values ('Ubuntu Linux','2023-05-01',2);
ERROR:  no partition of relation "part_tags" found for row
DETAIL:  Partition key of the failing row contains (ins_date) = (2023-05-01).

This happens because PostgreSQL does not have a correspondence between the date of 2023-05-01 and those present on the mapping of the child tables.

To eliminate this drawback, it is necessary to use a default partition where all the values that are not reflected in the mapping of the child tables will be inserted.

To do this let’s execute the following statement...