Book Image

Mastering PostgreSQL 15 - Fifth Edition

By : Hans-Jürgen Schönig
Book Image

Mastering PostgreSQL 15 - Fifth Edition

By: Hans-Jürgen Schönig

Overview of this book

Starting with an introduction to the newly released features of PostgreSQL 15, this updated fifth edition will help you get to grips with PostgreSQL administration and how to build dynamic database solutions for enterprise apps, including designing both physical and technical aspects of the system. You'll explore advanced PostgreSQL features, such as logical replication, database clusters, advanced indexing, and user management to manage and maintain your database. You'll then work with the PostgreSQL optimizer, configure PostgreSQL for high speed, and move from Oracle to PostgreSQL. Among the other skills that the book will help you build, you’ll cover transactions, handling recursions, working with JSON and JSONB data, and setting up a Patroni cluster. It will show you how to improve performance with query optimization. You'll also focus on managing network security and work with backups and replication while exploring useful PostgreSQL extensions that optimize the performance of large databases. By the end of this PostgreSQL book, you’ll be able to use your database to its utmost capacity by implementing advanced administrative tasks with ease.
Table of Contents (16 chapters)

Inspecting the log

If your system is in trouble, it makes sense to inspect the log to see what is going on. The important point is this: not all log entries are created equally. PostgreSQL has a hierarchy of log entries that range from DEBUG to PANIC.

For the administrator, the following three error levels are of great importance:

  • ERROR
  • FATAL
  • PANIC

ERROR is used for problems such as syntax errors, permission-related problems, and more. Your log will always contain error messages. The critical factor is this—how often does a certain type of error show up? Producing millions of syntax errors is certainly not an ideal strategy for running a database server.

FATAL is scarier than ERROR; you will see messages such as could not allocate memory for shared memory name or unexpected walreceiver state. In other words, these error messages are already really scary and will tell you that things are going wrong.

Finally, there is PANIC. If you come across...