PG_CTL(1)						  PostgreSQL Server Applications						 PG_CTL(1)

NAME

       pg_ctl - start, stop, or restart a PostgreSQL server

SYNOPSIS

       pg_ctl start [ -w ] [ -s ] [ -D datadir ] [ -l filename ] [ -o options ] [ -p path ]

       pg_ctl stop [ -W ] [ -s ] [ -D datadir ] [ -m  s[mart] | f[ast] | i[mmediate] ]

       pg_ctl restart [ -w ] [ -s ] [ -D datadir ] [ -m  s[mart] | f[ast] | i[mmediate] ] [ -o options ]

       pg_ctl reload [ -s ] [ -D datadir ]

       pg_ctl status [ -D datadir ]

DESCRIPTION

       pg_ctl  is a utility for starting, stopping, or restarting postmaster(1), the PostgreSQL backend server, or displaying the status of a run-
       ning postmaster. Although the postmaster can be started manually, pg_ctl encapsulates  tasks  such  as  redirecting  log  output,  properly
       detaching from the terminal and process group, and it provides convenient options for controlled shutdown.

       In  start  mode, a new postmaster is launched. The server is started in the background, the standard input attached to /dev/null. The stan-
       dard output and standard error are either appended to a log file, if the -l option is used, or are redirected to pg_ctl's  standard  output
       (not  standard  error). If no log file is chosen, the standard output of pg_ctl should be redirected to a file or piped to another process,
       for example a log rotating program, otherwise the postmaster will write its output the the controlling terminal (from the  background)  and
       will not leave the shell's process group.

       In stop mode, the postmaster that is running in the specified data directory is shut down. Three different shutdown methods can be selected
       with the -m option: ``Smart'' mode waits for all the clients to disconnect. This is the default. ``Fast'' mode does not wait for clients to
       disconnect.  All  active  transactions are rolled back and clients are forcibly disconnected, then the database is shut down. ``Immediate''
       mode will abort all server processes without clean shutdown. This will lead to a recovery run on restart.

       restart mode effectively executes a stop followed by a start. This allows the changing of postmaster command line options.

       reload mode simply sends the postmaster a SIGHUP signal, causing it to reread its configuration files (postgresql.conf, pg_hba.conf, etc.).
       This allows changing of configuration-file options that do not require a complete restart to take effect.

       status mode checks whether a postmaster is running and if so displays the PID and the command line options that were used to invoke it.

OPTIONS

       -D datadir
	      Specifies the file system location of the database files. If this is omitted, the environment variable PGDATA is used.

       -l filename
	      Append  the  server log output to filename. If the file does not exist, it is created. The umask is set to 077, so access to the log
	      file from other users is disallowed by default.

       -m mode
	      Specifies the shutdown mode. mode may be smart, fast, or immediate, or the first letter of one of these three.

       -o options
	      Specifies options to be passed directly to postmaster.

	      The parameters are usually surrounded by single or double quotes to ensure that they are passed through as a group.

       -p path
	      Specifies the location of the postmaster executable. By default the postmaster is taken from the same directory as pg_ctl, or  fail-
	      ing  that,  the hard-wired installation directory. It is not necessary to use this option unless you are doing something unusual and
	      get errors that the postmaster was not found.

       -s     Only print errors, no informational messages.

       -w     Wait for the start or shutdown to complete. Times out after 60 seconds. This is the default for shutdowns.

       -W     Do not wait for start or shutdown to complete. This is the default for starts and restarts.

ENVIRONMENT

       PGDATA Default data direction location

       For others, see postmaster(1).

FILES

       If the file postmaster.opts.default exists in the data directory, the contents of the file will be passed as  options  to  the  postmaster,
       unless overridden by the -o option.

NOTES

       Waiting	for  complete start is not a well-defined operation and may fail if access control is set up so that a local client cannot connect
       without manual interaction. It should be avoided.

EXAMPLES

   STARTING THE POSTMASTER
       To start up a postmaster:

       $ pg_ctl start

       An example of starting the postmaster, blocking until the postmaster comes up is:

       $ pg_ctl -w start

       For a postmaster using port 5433, and running without fsync, use:

       $ pg_ctl -o "-F -p 5433" start

   STOPPING THE POSTMASTER
       $ pg_ctl stop

       stops the postmaster. Using the -m switch allows one to control how the backend shuts down.

   RESTARTING THE POSTMASTER
       This is almost equivalent to stopping the postmaster and starting it again except that pg_ctl saves and reuses  the  command  line  options
       that were passed to the previously running instance. To restart the postmaster in the simplest form:

       $ pg_ctl restart

       To restart postmaster, waiting for it to shut down and to come up:

       $ pg_ctl -w restart

       To restart using port 5433 and disabling fsync after restarting:

       $ pg_ctl -o "-F -p 5433" restart

   SHOWING POSTMASTER STATUS
       Here is a sample status output from pg_ctl:

       $ pg_ctl status
       pg_ctl: postmaster is running (pid: 13718)
       Command line was:
       /usr/local/pgsql/bin/postmaster '-D' '/usr/local/pgsql/data' '-p' '5433' '-B' '128'

       This is the command line that would be invoked in restart mode.

SEE ALSO

       postmaster(1), PostgreSQL Administrator's Guide

Application							    2002-11-22								 PG_CTL(1)