In order to create a database, the PostgreSQL server must be up and running (see Section 16.3, “Starting the Database Server”).
Databases are created with the SQL command CREATE DATABASE:
CREATE DATABASE name
;
where name
follows the usual rules for
SQL identifiers. The current user automatically
becomes the owner of the new database. It is the privilege of the
owner of a database to remove it later on (which also removes all
the objects in it, even if they have a different owner).
The creation of databases is a restricted operation. See Section 17.2, “User Attributes” for how to grant permission.
Since you need to be connected to the database server in order to
execute the CREATE DATABASE
command, the
question remains how the first database at any given
site can be created. The first database is always created by the
initdb
command when the data storage area is
initialized. (See Section 16.2, “Creating a Database Cluster”.) This
database is called
template1
. So to
create the first “real” database you can connect to
template1
.
The name template1
is no accident: when a new
database is created, the template database is essentially cloned.
This means that any changes you make in template1
are
propagated to all subsequently created databases. This implies that
you should not use the template database for real work, but when
used judiciously this feature can be convenient. More details
appear in Section 18.3, “Template Databases”.
As a convenience, there is a program that you can
execute from the shell to create new databases,
createdb
.
createdb dbname
createdb
does no magic. It connects to the template1
database and issues the CREATE DATABASE
command,
exactly as described above.
The createdb reference page contains the invocation
details. Note that createdb
without any arguments will create
a database with the current user name, which may or may not be what
you want.
Chapter 19, Client Authentication contains information about how to restrict who can connect to a given database.
Sometimes you want to create a database for someone else. That user should become the owner of the new database, so he can configure and manage it himself. To achieve that, use one of the following commands:
CREATE DATABASEdbname
OWNERusername
;
from the SQL environment, or
createdb -Ousername
dbname
You must be a superuser to be allowed to create a database for someone else.