CREATE DATABASE
Creates a new database.
Synopsis
CREATE DATABASE name
[ [WITH] [OWNER [=] <user_name>]
[TEMPLATE [=] <template>]
[TABLESPACE [=] <tablespace_name>]
[ALLOW_CONNECTIONS [=] <allowconn>]
[CONNECTION LIMIT [=] <connlimit> ]
[IS_TEMPLATE [=] <istemplate> ] ]
Description
CREATE DATABASE creates a new database.
To create a database, you must be a superuser or have the special CREATEDB privilege. See CREATE ROLE.
The creator becomes the owner of the new database by default. Superusers can create databases owned by other users by using the OWNER clause. They can even create databases owned by users with no special privileges. Non-superusers with CREATEDB privilege can only create databases owned by themselves.
By default, the new database will be created by cloning the standard system database template1. A different template can be specified by writing TEMPLATE name. In particular, by writing TEMPLATE template0, you can create a clean database containing only the standard objects predefined by Apache Cloudberry. This is useful if you wish to avoid copying any installation-local objects that may have been added to template1.
Parameters
name
The name of a database to create.
user_name
The name of the database user who will own the new database, or DEFAULT to use the default owner (the user running the command). To create a database owned by another role, you must be a direct or indirect member of that role, or be a superuser.
template
The name of the template from which to create the new database, or DEFAULT to use the default template (template1).
tablespace_name
The name of the tablespace that will be associated with the new database, or DEFAULT to use the template database's tablespace. This tablespace will be the default tablespace used for objects created in this database. See CREATE TABLESPACE for more information.
allowconn
If false, then no one can connect to this database. The default is true, allowing connections (except as restricted by other mechanisms, such as GRANT/REVOKE CONNECT).
connlimit
The maximum number of concurrent connections allowed to this database on the coordinator. The default is -1, no limit. Apache Cloudberry superusers are exempt from this limit.
istemplate
If true, then this database can be cloned by any user with CREATEDB privileges; if false (the default), then only superusers or the owner of the database can clone it. Note that template databases cannot be dropped.
Optional parameters can be written in any order, not only the order illustrated above.
Notes
CREATE DATABASE cannot be run inside a transaction block.
Errors along the line of “could not initialize database directory” are most likely related to insufficient permissions on the data directory, a full disk, or other file system problems.
Use DROP DATABASE to remove a database.
The program createdb is a wrapper program around this command, provided for convenience.
Database-level configuration parameters (set via ALTER DATABASE) and database-level permissions (set via GRANT) are not copied from the template database.
Although it is possible to copy a database other than template1 by specifying its name as the template, this is not (yet) intended as a general-purpose "COPY DATABASE" facility. The principal limitation is that no other sessions can be connected to the template database while it is being copied. CREATE DATABASE will fail if any other connection exists when it starts; otherwise, new connections to the template database are locked out until CREATE DATABASE completes.
The CONNECTION LIMIT option is enforced approximately; if two new sessions start at about the same time when just one connection “slot” remains for the database, it is possible that both will fail. Also, the limit is not enforced against superusers or background worker processes.
Examples
To create a new database:
CREATE DATABASE mydatabase;
To create a database sales owned by user salesapp with a default tablespace of salesspace:
CREATE DATABASE sales OWNER salesapp TABLESPACE salesspace;
Compatibility
There is no CREATE DATABASE statement in the SQL standard. Databases are equivalent to catalogs, whose creation is implementation-defined.
