Book Image

PostgreSQL Administration Cookbook, 9.5/9.6 Edition - Third Edition

Book Image

PostgreSQL Administration Cookbook, 9.5/9.6 Edition - Third Edition

Overview of this book

PostgreSQL is a powerful opensource database management system; now recognized as the expert's choice for a wide range of applications, it has an enviable reputation for performance and stability. PostgreSQL provides an integrated feature set comprising relational database features, object-relational, text search, Geographical Info Systems, analytical tools for big data and JSON/XML document management. Starting with short and simple recipes, you will soon dive into core features, such as configuration, server control, tables, and data. You will tackle a variety of problems a database administrator usually encounters, from creating tables to managing views, from improving performance to securing your database, and from using monitoring tools to using storage engines. Recipes based on important topics such as high availability, concurrency, replication, backup and recovery, as well as diagnostics and troubleshooting are also given special importance. By the end of this book, you will have all the knowledge you need to run, manage, and maintain PostgreSQL efficiently.
Table of Contents (13 chapters)

Using a connection service file

As the number of connection options grows, you may want to consider using a connection service file.

The connection service file allows you to give a single name to a set of connection parameters. This can be accessed centrally to avoid the need for individual users to know the host and port of the database, and it is more resistant to future change.

You can set up a system-wide file as well as individual per-user files. The default file paths for these files are /etc/pg_service.conf and ~/.pg_service.conf respectively.

A system-wide connection file controls service names for all users from a single place, while a per-user file applies only to that particular user. Keep in mind that the per-user file overrides the system-wide file: if a service is defined in both the files, then the definition in the per-user file will prevail.

How to do it...

First, create a file named pg_service.conf with the following content:

[dbservice1] 
host=postgres1
port=5432
dbname=postgres

You can then copy it either to /etc/pg_service.conf or another agreed central location. You can then set the PGSYSCONFDIR environment variable to that directory location.

Alternatively, you can copy it to ~/.pg_service.conf. If you want to use a different name, set PGSERVICEFILE. Either way, you can then specify a connection string like the following:

service=dbservice1 user=sriggs

The service can also be set using an environment variable named PGSERVICE.

How it works...

This feature applies to libpq connections only, so it does not apply to JDBC.

The connection service file can also be used to specify the user, though that would mean that the username would be shared.

The pg_service.conf and .pgpass files can work together, or you can use just one of the two as you choose. Note that the pg_service.conf file is shared, so it is not a suitable place for passwords. The per-user connection service file is not shared, but in any case,
it seems best to keep things separate and confine passwords to .pgpass.