CREATE DATABASE
7
SQL - Language Statements
CREATE DATABASE
create a new database
CREATE DATABASE
CREATE DATABASE name
[ [ WITH ] [ OWNER [=] user_name ]
[ TEMPLATE [=] template ]
[ ENCODING [=] encoding ]
[ LC_COLLATE [=] lc_collate ]
[ LC_CTYPE [=] lc_ctype ]
[ TABLESPACE [=] tablespace ]
[ CONNECTION LIMIT [=] connlimit ] ]
Description
CREATE DATABASE creates a new
PostgreSQL database.
To create a database, you must be a superuser or have the special
CREATEDB> privilege.
See .
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 virgin
database 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
. See below for
additional restrictions.
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.
tablespace
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
for more information.
connlimit
How many concurrent connections can be made
to this database. -1 (the default) means no limit.
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 to remove a database.
The program is a
wrapper program around this command, provided for convenience.
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 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.
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.
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> which supports the ISO-8859-1
character set:
CREATE DATABASE music ENCODING 'LATIN1' TEMPLATE template0;
In this example, the TEMPLATE template0> clause would only
be required if template1>'s encoding is not ISO-8859-1.
Note that changing encoding might require selecting new
LC_COLLATE> and LC_CTYPE> settings as well.
Compatibility
There is no CREATE DATABASE statement in the SQL
standard. Databases are equivalent to catalogs, whose creation is
implementation-defined.
See Also