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

Reducing the number of rows returned

Although the problem is often producing many rows in the first place, it is made worse by returning all of the unnecessary rows to the client. This is especially true if the client and server are not on the same host.

Here are some ways to reduce the traffic between the client and server.

How to do it…

Consider the following scenario: a full-text search returns 10,000 documents, but only the first 20 are displayed to users. In this case, order the documents by rank on the server, and return only the top 20 that actually need to be displayed:

SELECT title, ts_rank_cd(body_tsv, query, 20) AS text_rank
FROM articles, plainto_tsquery('spicy potatoes') AS query
WHERE body_tsv @@ query

If you need the next 20 documents, don't just query with a limit of 40 and throw away the first 20. Instead, use OFFSET 20 LIMIT 20 to return the next 20 documents.

To gain some stability so that documents with the same rank still come out in the same...