CREATE DATABASE(7) PostgreSQL 15.7 Documentation CREATE DATABASE(7)
NAME
CREATE_DATABASE - create a new database
SYNOPSIS
CREATE DATABASE name
[ WITH ] [ OWNER [=] user_name ]
[ TEMPLATE [=] template ]
[ ENCODING [=] encoding ]
[ STRATEGY [=] strategy ]
[ LOCALE [=] locale ]
[ LC_COLLATE [=] lc_collate ]
[ LC_CTYPE [=] lc_ctype ]
[ ICU_LOCALE [=] icu_locale ]
[ LOCALE_PROVIDER [=] locale_provider ]
[ COLLATION_VERSION = collation_version ]
[ TABLESPACE [=] tablespace_name ]
[ ALLOW_CONNECTIONS [=] allowconn ]
[ CONNECTION LIMIT [=] connlimit ]
[ IS_TEMPLATE [=] istemplate ]
[ OID [=] oid ]
DESCRIPTION
CREATE DATABASE creates a new PostgreSQL database.
To create a database, you must be a superuser or have the special
CREATEDB privilege. See CREATE ROLE (CREATE_ROLE(7)).
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 pristine database (one where no user-defined objects
exist and where the system objects have not been altered) containing
only the standard objects predefined by your version of PostgreSQL.
This is useful if you wish to avoid copying any installation-local
objects that might have been added to template1.
PARAMETERS
name
The name of a database to create.
user_name
The role name of the user who will own the new database, or DEFAULT
to use the default (namely, the user executing 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).
encoding
Character set encoding to use in the new database. Specify a string
constant (e.g., 'SQL_ASCII'), or an integer encoding number, or
DEFAULT to use the default encoding (namely, the encoding of the
template database). The character sets supported by the PostgreSQL
server are described in Section 24.3.1. See below for additional
restrictions.
strategy
Strategy to be used in creating the new database. If the WAL_LOG
strategy is used, the database will be copied block by block and
each block will be separately written to the write-ahead log. This
is the most efficient strategy in cases where the template database
is small, and therefore it is the default. The older FILE_COPY
strategy is also available. This strategy writes a small record to
the write-ahead log for each tablespace used by the target
database. Each such record represents copying an entire directory
to a new location at the filesystem level. While this does reduce
the write-ahead log volume substantially, especially if the
template database is large, it also forces the system to perform a
checkpoint both before and after the creation of the new database.
In some situations, this may have a noticeable negative impact on
overall system performance.
locale
This is a shortcut for setting LC_COLLATE and LC_CTYPE at once.
Tip
The other locale settings lc_messages, lc_monetary, lc_numeric,
and lc_time are not fixed per database and are not set by this
command. If you want to make them the default for a specific
database, you can use ALTER DATABASE ... SET.
lc_collate
Collation order (LC_COLLATE) to use in the new database. This
affects the sort order applied to strings, e.g., in queries with
ORDER BY, as well as the order used in indexes on text columns. The
default is to use the collation order of the template database. See
below for additional restrictions.
lc_ctype
Character classification (LC_CTYPE) to use in the new database.
This affects the categorization of characters, e.g., lower, upper
and digit. The default is to use the character classification of
the template database. See below for additional restrictions.
icu_locale
Specifies the ICU locale ID if the ICU locale provider is used.
locale_provider
Specifies the provider to use for the default collation in this
database. Possible values are: icu, libc. libc is the default. The
available choices depend on the operating system and build options.
collation_version
Specifies the collation version string to store with the database.
Normally, this should be omitted, which will cause the version to
be computed from the actual version of the database collation as
provided by the operating system. This option is intended to be
used by pg_upgrade for copying the version from an existing
installation.
See also ALTER DATABASE (ALTER_DATABASE(7)) for how to handle
database collation version mismatches.
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
(CREATE_TABLESPACE(7)) 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
How many concurrent connections can be made to this database. -1
(the default) means no 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.
oid
The object identifier to be used for the new database. If this
parameter is not specified, PostgreSQL will choose a suitable OID
automatically. This parameter is primarily intended for internal
use by pg_upgrade, and only pg_upgrade can specify a value less
than 16384.
Optional parameters can be written in any order, not only the order
illustrated above.
NOTES
CREATE DATABASE cannot be executed 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(1) 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. See
Section 23.3 for more information.
The character set encoding specified for the new database must be
compatible with the chosen locale settings (LC_COLLATE and LC_CTYPE).
If the locale is C (or equivalently POSIX), then all encodings are
allowed, but for other locale settings there is only one encoding that
will work properly. (On Windows, however, UTF-8 encoding can be used
with any locale.) CREATE DATABASE will allow superusers to specify
SQL_ASCII encoding regardless of the locale settings, but this choice
is deprecated and may result in misbehavior of character-string
functions if data that is not encoding-compatible with the locale is
stored in the database.
The encoding and locale settings must match those of the template
database, except when template0 is used as template. This is because
other databases might contain data that does not match the specified
encoding, or might contain indexes whose sort ordering is affected by
LC_COLLATE and LC_CTYPE. Copying such data would result in a database
that is corrupt according to the new settings. template0, however, is
known to not contain any data or indexes that would be affected.
There is currently no option to use a database locale with
nondeterministic comparisons (see CREATE COLLATION for an explanation).
If this is needed, then per-column collations would need to be used.
The CONNECTION LIMIT option is only 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 lusiadas;
To create a database sales owned by user salesapp with a default
tablespace of salesspace:
CREATE DATABASE sales OWNER salesapp TABLESPACE salesspace;
To create a database music with a different locale:
CREATE DATABASE music
LOCALE 'sv_SE.utf8'
TEMPLATE template0;
In this example, the TEMPLATE template0 clause is required if the
specified locale is different from the one in template1. (If it is not,
then specifying the locale explicitly is redundant.)
To create a database music2 with a different locale and a different
character set encoding:
CREATE DATABASE music2
LOCALE 'sv_SE.iso885915'
ENCODING LATIN9
TEMPLATE template0;
The specified locale and encoding settings must match, or an error will
be reported.
Note that locale names are specific to the operating system, so that
the above commands might not work in the same way everywhere.
COMPATIBILITY
There is no CREATE DATABASE statement in the SQL standard. Databases
are equivalent to catalogs, whose creation is implementation-defined.
SEE ALSO
ALTER DATABASE (ALTER_DATABASE(7)), DROP DATABASE (DROP_DATABASE(7))
PostgreSQL 15.7 2024 CREATE DATABASE(7)
postgresql 15.7 - Generated Wed May 22 08:11:22 CDT 2024