initdb — create a new PostgreSQL database cluster
initdb [option...]  [ --pgdata  |   -D ] directory 
   initdb creates a new
   PostgreSQL database cluster.  A database
   cluster is a collection of databases that are managed by a single
   server instance.
  
   Creating a database cluster consists of creating the directories in
   which the database data will live, generating the shared catalog
   tables (tables that belong to the whole cluster rather than to any
   particular database), and creating the template1
   and postgres databases. When you later create a
   new database, everything in the template1 database is
   copied.  (Therefore, anything installed in template1
   is automatically copied into each database created later.)
   The postgres database is a default database meant
   for use by users, utilities and third party applications.
  
   Although initdb will attempt to create the
   specified data directory, it might not have permission if the parent
   directory of the desired data directory is root-owned. To initialize
   in such a setup, create an empty data directory as root, then use
   chown to assign ownership of that directory to the
   database user account, then su to become the
   database user to run initdb.
  
   initdb must be run as the user that will own the
   server process, because the server needs to have access to the
   files and directories that initdb creates.
   Since the server cannot be run as root, you must not run
   initdb as root either.  (It will in fact refuse
   to do so.)
  
    For security reasons the new cluster created by initdb
    will only be accessible by the cluster owner by default.  The
    --allow-group-access option allows any user in the same
    group as the cluster owner to read files in the cluster.  This is useful
    for performing backups as a non-privileged user.
  
   initdb initializes the database cluster's default
   locale and character set encoding. The character set encoding,
   collation order (LC_COLLATE) and character set classes
   (LC_CTYPE, e.g. upper, lower, digit) can be set separately
   for a database when it is created. initdb determines
   those settings for the template1 database, which will
   serve as the default for all other databases.
  
   To alter the default collation order or character set classes, use the
   --lc-collate and --lc-ctype options.
   Collation orders other than C or POSIX also have
   a performance penalty.  For these reasons it is important to choose the
   right locale when running initdb.
  
   The remaining locale categories can be changed later when the server
   is started.  You can also use --locale to set the
   default for all locale categories, including collation order and
   character set classes. All server locale values (lc_*) can
   be displayed via SHOW ALL.
   More details can be found in Section 23.1.
  
   To alter the default encoding, use the --encoding.
   More details can be found in Section 23.3.
  
-A authmethod--auth=authmethod
        This option specifies the default authentication method for local
        users used in pg_hba.conf (host
        and local lines).  initdb will
        prepopulate pg_hba.conf entries using the
        specified authentication method for non-replication as well as
        replication connections.
       
        Do not use trust unless you trust all local users on your
        system.  trust is the default for ease of installation.
       
--auth-host=authmethod
        This option specifies the authentication method for local users via
        TCP/IP connections used in pg_hba.conf
        (host lines).
       
--auth-local=authmethod
        This option specifies the authentication method for local users via
        Unix-domain socket connections used in pg_hba.conf
        (local lines).
       
-D directory--pgdata=directory
        This option specifies the directory where the database cluster
        should be stored. This is the only information required by
        initdb, but you can avoid writing it by
        setting the PGDATA environment variable, which
        can be convenient since the database server
        (postgres) can find the database
        directory later by the same variable.
       
-E encoding--encoding=encoding
        Selects the encoding of the template database. This will also
        be the default encoding of any database you create later,
        unless you override it there.  The default is derived from the locale, or
        SQL_ASCII if that does not work. The character sets supported by
        the PostgreSQL server are described
        in Section 23.3.1.
       
-g--allow-group-access
        Allows users in the same group as the cluster owner to read all cluster
        files created by initdb.  This option is ignored
        on Windows as it does not support
        POSIX-style group permissions.
       
-k--data-checksumsUse checksums on data pages to help detect corruption by the I/O system that would otherwise be silent. Enabling checksums may incur a noticeable performance penalty. If set, checksums are calculated for all objects, in all databases. All checksum failures will be reported in the pg_stat_database view.
--locale=locale
        Sets the default locale for the database cluster.  If this
        option is not specified, the locale is inherited from the
        environment that initdb runs in. Locale
        support is described in Section 23.1.
       
--lc-collate=locale--lc-ctype=locale--lc-messages=locale--lc-monetary=locale--lc-numeric=locale--lc-time=locale
        Like --locale, but only sets the locale in
        the specified category.
       
--no-locale
        Equivalent to --locale=C.
       
-N--no-sync
        By default, initdb will wait for all files to be
        written safely to disk.  This option causes initdb
        to return without waiting, which is faster, but means that a
        subsequent operating system crash can leave the data directory
        corrupt.  Generally, this option is useful for testing, but should not
        be used when creating a production installation.
       
--pwfile=filename
        Makes initdb read the database superuser's password
        from a file.  The first line of the file is taken as the password.
       
-S--sync-onlySafely write all database files to disk and exit. This does not perform any of the normal initdb operations.
-T config--text-search-config=configSets the default text search configuration. See default_text_search_config for further information.
-U username--username=username
        Selects the user name of the database superuser. This defaults
        to the name of the effective user running
        initdb. It is really not important what the
        superuser's name is, but one might choose to keep the
        customary name postgres, even if the operating
        system user's name is different.
       
-W--pwprompt
        Makes initdb prompt for a password
        to give the database superuser. If you don't plan on using password
        authentication, this is not important.  Otherwise you won't be
        able to use password authentication until you have a password
        set up.
       
-X directory--waldir=directoryThis option specifies the directory where the write-ahead log should be stored.
--wal-segsize=sizeSet the WAL segment size, in megabytes. This is the size of each individual file in the WAL log. The default size is 16 megabytes. The value must be a power of 2 between 1 and 1024 (megabytes). This option can only be set during initialization, and cannot be changed later.
It may be useful to adjust this size to control the granularity of WAL log shipping or archiving. Also, in databases with a high volume of WAL, the sheer number of WAL files per directory can become a performance and management problem. Increasing the WAL file size will reduce the number of WAL files.
Other, less commonly used, options are also available:
-d--debug
        Print debugging output from the bootstrap backend and a few other
        messages of lesser interest for the general public.
        The bootstrap backend is the program initdb
        uses to create the catalog tables.  This option generates a tremendous
        amount of extremely boring output.
       
-L directory
        Specifies where initdb should find
        its input files to initialize the database cluster.  This is
        normally not necessary.  You will be told if you need to
        specify their location explicitly.
       
-n--no-clean
        By default, when initdb
        determines that an error prevented it from completely creating the database
        cluster, it removes any files it might have created before discovering
        that it cannot finish the job. This option inhibits tidying-up and is
        thus useful for debugging.
       
Other options:
-V--versionPrint the initdb version and exit.
-?--helpShow help about initdb command line arguments, and exit.
PGDATA
      Specifies the directory where the database cluster is to be
      stored; can be overridden using the -D option.
     
PG_COLOR
      Specifies whether to use color in diagnostics messages.  Possible values
      are always, auto,
      never.
     
TZSpecifies the default time zone of the created database cluster. The value should be a full time zone name (see Section 8.5.3).
This utility, like most other PostgreSQL utilities, also uses the environment variables supported by libpq (see Section 33.14).
   initdb can also be invoked via
   pg_ctl initdb.