There are mainly two types of backups that apply to PostgreSQL: the logical backup (also known as a cold backup) and the physical backup (also known as a hot backup). Depending on the type of backup you choose, the restore process will differ accordingly.
PostgreSQL ships will all the integrated tools to perform the classical logical backup, which in most cases suffices. However, PostgreSQL can easily be configured to support physical backups, which are useful when the size of the cluster becomes huge, as well as when you have particular needs, as you will discover later in this chapter.
But what is the difference between these two backup methods? As you can imagine, they both achieve the very same aim: allowing you to get a usable "copy" of your data to restore either on the same cluster or against another cluster. However, the difference between the two backup strategies come from the way data is extracted from the cluster...
