Creating a Database
Creating a Database
In order to create a database, the Tacnode server must be up and running (see "server-start").
Databases are created with the SQL command CREATE DATABASE:
where name
follows the usual rules for SQL identifiers. The current role automatically becomes the owner of the new database. It is the privilege of the owner of a database to remove it later (which also removes all the objects in it, even if they have a different owner).
The creation of databases is a restricted operation
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. This database is called postgres
. So to create the first “ordinary” database you can connect to postgres
.
A second database, template1
, is also created during database cluster initialization. Whenever a new database is created within the cluster, template1
is essentially cloned. This means that any changes you make in template1
are propagated to all subsequently created databases. Because of this, avoid creating objects in template1
unless you want them propagated to every newly created database. More details appear in Section 10.3.
As a convenience, there is a program you can execute from the shell to create new databases, createdb
.
createdb
does no magic. It connects to the postgres
database and issues the CREATE DATABASE
command, exactly as described above. The "app-createdb" reference page contains the invocation details. Note that createdb
without any arguments will create a database with the current user name.
Sometimes you want to create a database for someone else, and have them become the owner of the new database, so they can configure and manage it themselves. To achieve that, use one of the following commands:
from the SQL environment, or:
from the shell. Only the superuser is allowed to create a database for someone else (that is, for a role you are not a member of).