<!--
-$Header: /cvsroot/pgsql/doc/src/sgml/ref/create_database.sgml,v 1.30 2002/11/15 03:11:17 momjian Exp $
+doc/src/sgml/ref/create_database.sgml
PostgreSQL documentation
-->
<refentry id="SQL-CREATEDATABASE">
+ <indexterm zone="sql-createdatabase">
+ <primary>CREATE DATABASE</primary>
+ </indexterm>
+
<refmeta>
- <refentrytitle id="sql-createdatabase-title">CREATE DATABASE</refentrytitle>
+ <refentrytitle>CREATE DATABASE</refentrytitle>
+ <manvolnum>7</manvolnum>
<refmiscinfo>SQL - Language Statements</refmiscinfo>
</refmeta>
+
<refnamediv>
- <refname>
- CREATE DATABASE
- </refname>
- <refpurpose>
- create a new database
- </refpurpose>
+ <refname>CREATE DATABASE</refname>
+ <refpurpose>create a new database</refpurpose>
</refnamediv>
+
<refsynopsisdiv>
- <refsynopsisdivinfo>
- <date>1999-12-11</date>
- </refsynopsisdivinfo>
- <synopsis>
+<synopsis>
CREATE DATABASE <replaceable class="PARAMETER">name</replaceable>
- [ [ WITH ] [ OWNER [=] <replaceable class="parameter">dbowner</replaceable> ]
- [ LOCATION [=] '<replaceable class="parameter">dbpath</replaceable>' ]
+ [ [ WITH ] [ OWNER [=] <replaceable class="parameter">user_name</replaceable> ]
[ TEMPLATE [=] <replaceable class="parameter">template</replaceable> ]
- [ ENCODING [=] <replaceable class="parameter">encoding</replaceable> ] ]
- </synopsis>
-
- <refsect2 id="R2-SQL-CREATEDATABASE-1">
- <refsect2info>
- <date>1999-12-11</date>
- </refsect2info>
- <title>
- Inputs
- </title>
- <para>
+ [ ENCODING [=] <replaceable class="parameter">encoding</replaceable> ]
+ [ LC_COLLATE [=] <replaceable class="parameter">lc_collate</replaceable> ]
+ [ LC_CTYPE [=] <replaceable class="parameter">lc_ctype</replaceable> ]
+ [ TABLESPACE [=] <replaceable class="parameter">tablespace_name</replaceable> ]
+ [ IS_TEMPLATE [=] <replaceable class="parameter">istemplate</replaceable> ]
+ [ ALLOW_CONNECTIONS [=] <replaceable class="parameter">allowconn</replaceable> ]
+ [ CONNECTION LIMIT [=] <replaceable class="parameter">connlimit</replaceable> ] ]
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ <command>CREATE DATABASE</command> creates a new
+ <productname>PostgreSQL</productname> database.
+ </para>
+
+ <para>
+ To create a database, you must be a superuser or have the special
+ <literal>CREATEDB</> privilege.
+ See <xref linkend="SQL-CREATEUSER">.
+ </para>
+
+ <para>
+ By default, the new database will be created by cloning the standard
+ system database <literal>template1</>. A different template can be
+ specified by writing <literal>TEMPLATE
+ <replaceable class="parameter">name</replaceable></literal>. In particular,
+ by writing <literal>TEMPLATE template0</>, you can create a virgin
+ database containing only the standard objects predefined by your
+ version of <productname>PostgreSQL</productname>. This is useful
+ if you wish to avoid copying
+ any installation-local objects that might have been added to
+ <literal>template1</>.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
<variablelist>
<varlistentry>
<term><replaceable class="parameter">name</replaceable></term>
<listitem>
<para>
- The name of a database to create.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><replaceable class="parameter">dbowner</replaceable></term>
- <listitem>
- <para>
- Name of the database user who will own the new database,
- or <literal>DEFAULT</literal> to use the default (namely, the
- user executing the command).
+ The name of a database to create.
</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><replaceable class="parameter">dbpath</replaceable></term>
+ <term><replaceable class="parameter">user_name</replaceable></term>
<listitem>
<para>
- An alternate file-system location in which to store the new database,
- specified as a string literal;
- or <literal>DEFAULT</literal> to use the default location.
+ The role name of the user who will own the new database,
+ or <literal>DEFAULT</literal> 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.
</para>
</listitem>
</varlistentry>
<term><replaceable class="parameter">template</replaceable></term>
<listitem>
<para>
- Name of template from which to create the new database,
- or <literal>DEFAULT</literal> to use the default template
- (<literal>template1</literal>).
+ The name of the template from which to create the new database,
+ or <literal>DEFAULT</literal> to use the default template
+ (<literal>template1</literal>).
</para>
</listitem>
</varlistentry>
<term><replaceable class="parameter">encoding</replaceable></term>
<listitem>
<para>
- Multibyte encoding method to use in the new database. Specify
- a string literal name (e.g., <literal>'SQL_ASCII'</literal>),
- or an integer encoding number, or <literal>DEFAULT</literal>
- to use the default encoding.
+ Character set encoding to use in the new database. Specify
+ a string constant (e.g., <literal>'SQL_ASCII'</literal>),
+ or an integer encoding number, or <literal>DEFAULT</literal>
+ to use the default encoding (namely, the encoding of the
+ template database). The character sets supported by the
+ <productname>PostgreSQL</productname> server are described in
+ <xref linkend="multibyte-charset-supported">. See below for
+ additional restrictions.
</para>
</listitem>
</varlistentry>
- </variablelist>
- </para>
- </refsect2>
-
- <refsect2 id="R2-SQL-CREATEDATABASE-2">
- <refsect2info>
- <date>1999-12-11</date>
- </refsect2info>
- <title>
- Outputs
- </title>
- <para>
-
- <variablelist>
<varlistentry>
- <term><computeroutput>CREATE DATABASE</computeroutput></term>
+ <term><replaceable class="parameter">lc_collate</replaceable></term>
<listitem>
<para>
- Message returned if the command completes successfully.
+ Collation order (<literal>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.
</para>
</listitem>
</varlistentry>
-
<varlistentry>
- <term><computeroutput>ERROR: user '<replaceable class="parameter">username</replaceable>' is not allowed to create/drop databases</computeroutput></term>
+ <term><replaceable class="parameter">lc_ctype</replaceable></term>
<listitem>
<para>
- You must have the special <literal>CREATEDB</> privilege to create databases.
- See <xref linkend="SQL-CREATEUSER" endterm="SQL-CREATEUSER-title">.
+ Character classification (<literal>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.
</para>
</listitem>
</varlistentry>
-
-
- <varlistentry>
- <term><computeroutput>ERROR: createdb: database "<replaceable class="parameter">name</replaceable>" already exists</computeroutput></term>
- <listitem>
- <para>
- This occurs if a database with the <replaceable class="parameter">name</replaceable>
- specified already exists.
- </para>
- </listitem>
- </varlistentry>
-
<varlistentry>
- <term><computeroutput>ERROR: database path may not contain single quotes</computeroutput></term>
+ <term><replaceable class="parameter">tablespace_name</replaceable></term>
<listitem>
<para>
- The database location
- <replaceable class="parameter">dbpath</replaceable> cannot contain
- single quotes. This is required so that the shell commands that
- create the database directory can execute safely.
+ The name of the tablespace that will be associated with the
+ new database, or <literal>DEFAULT</literal> to use the
+ template database's tablespace. This
+ tablespace will be the default tablespace used for objects
+ created in this database. See
+ <xref linkend="sql-createtablespace">
+ for more information.
</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><computeroutput>ERROR: CREATE DATABASE: may not be called in a transaction block</computeroutput></term>
- <listitem>
- <para>
- If you have an explicit transaction block in progress you cannot call
- <command>CREATE DATABASE</command>. You must finish the transaction first.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term><computeroutput>ERROR: Unable to create database directory '<replaceable>path</replaceable>'.</computeroutput></term>
- <term><computeroutput>ERROR: Could not initialize database directory.</computeroutput></term>
+ <term><replaceable class="parameter">istemplate</replaceable></term>
+ <listitem>
+ <para>
+ 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.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">allowconn</replaceable></term>
+ <listitem>
+ <para>
+ If false then no one can connect to this database. The default is
+ true, allowing connections (except as restricted by other mechanisms,
+ such as <literal>GRANT</>/<literal>REVOKE CONNECT</>).
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">connlimit</replaceable></term>
<listitem>
<para>
- These are most likely related to insufficient permissions on the data
- directory, a full disk, or other file system problems. The user under
- which the database server is running must have access to the location.
+ How many concurrent connections can be made
+ to this database. -1 (the default) means no limit.
</para>
</listitem>
</varlistentry>
-
</variablelist>
- </para>
- </refsect2>
- </refsynopsisdiv>
-
- <refsect1 id="R1-SQL-CREATEDATABASE-1">
- <refsect1info>
- <date>1999-12-11</date>
- </refsect1info>
- <title>
- Description
- </title>
- <para>
- <command>CREATE DATABASE</command> creates a new
- <productname>PostgreSQL</productname> database.
- </para>
-
- <para>
- Normally, the creator becomes the owner of the new database.
- Superusers can create databases owned by other users using the
- <option>OWNER</> clause. They can even create databases owned by
- users with no special privileges. Non-superusers with <literal>CREATEDB</>
- privilege can only create databases owned by themselves.
- </para>
-
- <para>
- An alternate location can be specified in order to,
- for example, store the database on a different disk.
- The path must have been prepared with the
- <xref linkend="APP-INITLOCATION" endterm="APP-INITLOCATION-title">
- command.
- </para>
- <para>
- If the path name does not contain a slash, it is interpreted
- as an environment variable name, which must be known to the
- server process. This way the database administrator can
- exercise control over locations in which databases can be created.
- (A customary choice is, e.g., <envar>PGDATA2</envar>.)
- If the server is compiled with <literal>ALLOW_ABSOLUTE_DBPATHS</literal>
- (not so by default), absolute path names, as identified by
- a leading slash
- (e.g., <filename>/usr/local/pgsql/data</filename>),
- are allowed as well.
- </para>
-
- <para>
- By default, the new database will be created by cloning the standard
- system database <literal>template1</>. A different template can be
- specified by writing <literal>TEMPLATE =</>
- <replaceable class="parameter">name</replaceable>. In particular,
- by writing <literal>TEMPLATE = template0</>, you can create a virgin
- database containing only the standard objects predefined by your
- version of <productname>PostgreSQL</productname>. This is useful
- if you wish to avoid copying
- any installation-local objects that may have been added to
- <literal>template1</>.
- </para>
-
- <para>
- The optional encoding parameter allows selection of the database encoding,
- if your server was compiled with multibyte encoding support. When not
- specified, it defaults to the encoding used by the selected template
- database.
- </para>
<para>
Optional parameters can be written in any order, not only the order
illustrated above.
</para>
+ </refsect1>
+
+ <refsect1>
+ <title>Notes</title>
- <refsect2 id="R2-SQL-CREATEDATABASE-3">
- <refsect2info>
- <date>1999-12-11</date>
- </refsect2info>
- <title>
- Notes
- </title>
<para>
- <command>CREATE DATABASE</command> is a <productname>PostgreSQL</productname>
- language extension.
+ <command>CREATE DATABASE</> cannot be executed inside a transaction
+ block.
</para>
+
<para>
- Use <xref linkend="SQL-DROPDATABASE" endterm="SQL-DROPDATABASE-title"> to remove a database.
+ Errors along the line of <quote>could not initialize database directory</>
+ are most likely related to insufficient permissions on the data
+ directory, a full disk, or other file system problems.
</para>
+
<para>
- The program <xref linkend="APP-CREATEDB" endterm="APP-CREATEDB-title"> is a
- shell script wrapper around this command, provided for convenience.
+ Use <xref linkend="SQL-DROPDATABASE"> to remove a database.
</para>
<para>
- There are security and data integrity issues
- involved with using alternate database locations
- specified with absolute path names, and by default
- only an environment variable known to the backend may be
- specified for an alternate location.
- See the Administrator's Guide for more information.
+ The program <xref linkend="APP-CREATEDB"> is a
+ wrapper program around this command, provided for convenience.
</para>
-<!--
-comment from Olly; response from Thomas...
- <comment>
- initlocation does not create a PG_VERSION file in the specified location.
- How will PostgreSQL handle the situation if it is upgraded to an
- incompatible database version?
- </comment>
- Hmm. This isn't an issue since the upgrade would do
- a dump/reload from the main database area also.
- Not sure if the dump/reload would guarantee that
- the alternate data area gets refreshed though...
--->
+ <para>
+ Database-level configuration parameters (set via <xref
+ linkend="sql-alterdatabase">) are not copied from the template
+ database.
+ </para>
<para>
Although it is possible to copy a database other than <literal>template1</>
by specifying its name as the template, this is not (yet) intended as
- a general-purpose COPY DATABASE facility.
- We recommend that databases used as templates be treated as read-only.
- See the <citetitle>Administrator's Guide</> for more information.
+ a general-purpose <quote><command>COPY DATABASE</command></quote> facility.
+ The principal limitation is that no other sessions can be connected to
+ the template database while it is being copied. <command>CREATE
+ DATABASE</> will fail if any other connection exists when it starts;
+ otherwise, new connections to the template database are locked out
+ until <command>CREATE DATABASE</> completes.
+ See <xref linkend="manage-ag-templatedbs"> for more information.
+ </para>
+
+ <para>
+ The character set encoding specified for the new database must be
+ compatible with the chosen locale settings (<literal>LC_COLLATE</> and
+ <literal>LC_CTYPE</>). If the locale is <literal>C</> (or equivalently
+ <literal>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.)
+ <command>CREATE DATABASE</> will allow superusers to specify
+ <literal>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.
+ </para>
+
+ <para>
+ The encoding and locale settings must match those of the template database,
+ except when <literal>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
+ <literal>LC_COLLATE</> and <literal>LC_CTYPE</>. Copying such data would
+ result in a database that is corrupt according to the new settings.
+ <literal>template0</literal>, however, is known to not contain any data or
+ indexes that would be affected.
+ </para>
+
+ <para>
+ The <literal>CONNECTION LIMIT</> option is only enforced approximately;
+ if two new sessions start at about the same time when just one
+ connection <quote>slot</> remains for the database, it is possible that
+ both will fail. Also, the limit is not enforced against superusers.
</para>
- </refsect2>
</refsect1>
- <refsect1 id="R1-SQL-CREATEDATABASE-2">
- <title>
- Usage
- </title>
+ <refsect1>
+ <title>Examples</title>
+
<para>
To create a new database:
- <programlisting>
-<prompt>olly=></prompt> <userinput>create database lusiadas;</userinput>
- </programlisting>
+<programlisting>
+CREATE DATABASE lusiadas;
+</programlisting>
</para>
<para>
- To create a new database in an alternate area <filename>~/private_db</filename>:
-
- <programlisting>
-<prompt>$</prompt> <userinput>mkdir private_db</userinput>
-<prompt>$</prompt> <userinput>initlocation ~/private_db</userinput>
- <computeroutput>
-The location will be initialized with username "olly".
-This user will own all the files and must also own the server process.
-Creating directory /home/olly/private_db
-Creating directory /home/olly/private_db/base
-
-initlocation is complete.
- </computeroutput>
-
-<prompt>$</prompt> <userinput>psql olly</userinput>
-<computeroutput>
-Welcome to psql, the PostgreSQL interactive terminal.
-
-Type: \copyright for distribution terms
- \h for help with SQL commands
- \? for help on internal slash commands
- \g or terminate with semicolon to execute query
- \q to quit
-
-<prompt>olly=></prompt></computeroutput> <userinput>CREATE DATABASE elsewhere WITH LOCATION = '/home/olly/private_db';</userinput>
-<computeroutput>CREATE DATABASE</computeroutput>
- </programlisting>
+ To create a database <literal>sales</> owned by user <literal>salesapp</>
+ with a default tablespace of <literal>salesspace</>:
+
+<programlisting>
+CREATE DATABASE sales OWNER salesapp TABLESPACE salesspace;
+</programlisting>
+ </para>
+
+ <para>
+ To create a database <literal>music</> which supports the ISO-8859-1
+ character set:
+
+<programlisting>
+CREATE DATABASE music ENCODING 'LATIN1' TEMPLATE template0;
+</programlisting>
+
+ In this example, the <literal>TEMPLATE template0</> clause would only
+ be required if <literal>template1</>'s encoding is not ISO-8859-1.
+ Note that changing encoding might require selecting new
+ <literal>LC_COLLATE</> and <literal>LC_CTYPE</> settings as well.
</para>
</refsect1>
- <refsect1 id="R1-SQL-CREATEDATABASE-4">
- <title>
- Compatibility
- </title>
-
- <refsect2 id="R2-SQL-CREATEDATABASE-4">
- <refsect2info>
- <date>1998-04-15</date>
- </refsect2info>
- <title>
- SQL92
- </title>
- <para>
- There is no <command>CREATE DATABASE</command> statement in SQL92.
- Databases are equivalent to catalogs, whose creation is
- implementation-defined.
- </para>
- </refsect2>
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ There is no <command>CREATE DATABASE</command> statement in the SQL
+ standard. Databases are equivalent to catalogs, whose creation is
+ implementation-defined.
+ </para>
</refsect1>
-</refentry>
-<!-- Keep this comment at the end of the file
-Local variables:
-mode: sgml
-sgml-omittag:nil
-sgml-shorttag:t
-sgml-minimize-attributes:nil
-sgml-always-quote-attributes:t
-sgml-indent-step:1
-sgml-indent-data:t
-sgml-parent-document:nil
-sgml-default-dtd-file:"../reference.ced"
-sgml-exposed-tags:nil
-sgml-local-catalogs:"/usr/lib/sgml/catalog"
-sgml-local-ecat-files:nil
-End:
--->
+ <refsect1>
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-alterdatabase"></member>
+ <member><xref linkend="sql-dropdatabase"></member>
+ </simplelist>
+ </refsect1>
+
+</refentry>