PostgreSQL 12 High Availability Cookbook - Third Edition

How it works...

That is a lot of questions, and the list isn't even complete. It is, however, a very good start. Notice how we want to know who (or what) is using the database on a regular basis. This is not the same as a user who connects to the database. In this context, we want to know the category of user. Is it a business department, another department, a critical application component, or even just a regular website user? Each of these will have different expectations, reactions, usage times, and impact.

The next question we need to answer is how uptime is defined. One frequently quoted value is the number of nines, referring to a percentage approaching 100 percent. Three nines, for example, would be 99.9 percent of a year, which is ...