PostgreSQL, Second Edition

Managing Databases

PostgreSQL stores data in a collection of operating system files. At the highest level of organization, you find a cluster. A cluster is a collection of databases (which, in turn, is a collection of schemas).

Creating a New Cluster

You create a new cluster using the initdb program. Note that initdb is an external program, not a command that you would execute in a PostgreSQL client.

When you run initdb, you are creating the data files that define a cluster. The most important command-line argument to initdb is —pgdata= cluster-location^[4]. The —pgdata argument tells initdb the name of the directory that should contain the new cluster. For example, if you execute the command

^[4] There are actually three ways to specify the cluster ...