|The PostgreSQL 9.0 Reference Manual - Volume 1B - SQL Command Reference
by The PostgreSQL Global Development Group
Paperback (6"x9"), 488 pages
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pg_ctl -- initialize, start, stop, or restart a PostgreSQL server
pg_ctl init[db] [-s] [-D datadir] [-o options]
pg_ctl start [-w] [-t seconds] [-s] [-D datadir] [-l filename] [-o options] [-p path] [-c]
pg_ctl stop [-W] [-t seconds] [-s] [-D datadir] [-ms[mart] | f[ast] | i[mmediate]]
pg_ctl restart [-w] [-t seconds] [-s] [-D datadir] [-c] [-ms[mart] | f[ast] | i[mmediate]] [-o options]
pg_ctl reload [-s] [-D datadir]
pg_ctl status [-D datadir]
pg_ctl kill [signal_name] [process_id]
pg_ctl register [-N servicename] [-U username] [-P password] [-D datadir] [-w] [-t seconds] [-o options]
pg_ctl unregister [-N servicename]
pg_ctl is a utility for initializing a
PostgreSQL database cluster, starting,
stopping, or restarting the PostgreSQL
backend server (
postgres), or displaying the
status of a running server. Although the server can be started
manually, pg_ctl encapsulates tasks such
as redirecting log output and properly detaching from the terminal
and process group. It also provides convenient options for
initdb mode creates a
PostgreSQL database cluster. A database
cluster is a collection of databases that are managed by a single
server instance. This mode invokes the
initdb for details.
start mode, a new server is launched. The
server is started in the background, and standard input is attached
to ‘/dev/null’ (or
nul on Windows).
On Unix-like systems, by default, the server's standard output and
standard error are send to pg_ctl's
standard output (not standard error). The standard output of
pg_ctl should then be redirected to a
file or piped to another process such as a log rotating program
like rotatelogs; otherwise
will write its output to the controlling terminal (from the
background) and will not leave the shell's process group. On
Windows, by default the server's standard output and standard error
are sent to the terminal. These default behaviors can be changed
-l to append server output to a log file.
stop mode, the server that is running in
the specified data directory is shut down. Three different
shutdown methods can be selected with the
option: “Smart” mode waits for online backup mode
to finish and all the clients to disconnect. This is the default.
If the server is in recovery, recovery and streaming replication
will be terminated once all clients have disconnected.
“Fast” mode does not wait for clients to disconnect and
will terminate an online backup in progress. All active transactions are
rolled back and clients are forcibly disconnected, then the
server is shut down. “Immediate” mode will abort
all server processes without a clean shutdown. This will lead to
a recovery run on restart.
restart mode effectively executes a stop followed
by a start. This allows changing the
reload mode simply sends the
postgres process a
signal, causing it to reread its configuration files
‘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 server is running in
the specified data directory. If it is, the PID
and the command line options that were used to invoke it are
kill mode allows you to send a signal to a specified
process. This is particularly valuable for Microsoft Windows
which does not have a kill command. Use
--help to see a list of supported signal names.
register mode allows you to register a system service
on Microsoft Windows.
unregister mode allows you to unregister a system service
on Microsoft Windows, previously registered with the
- Attempt to allow server crashes to produce core files, on platforms where this available, by lifting any soft resource limit placed on them. This is useful in debugging or diagnosing problems by allowing a stack trace to be obtained from a failed server process.
Specifies the file system location of the database files. If
this is omitted, the environment variable
Append the server log output to
filename. If the file does not
exist, it is created. The
umaskis set to 077, so access to the log file from other users is disallowed by default.
Specifies the shutdown mode. mode
immediate, or the first letter of one of these three.
Specifies options to be passed directly to the
postgrescommand. The options are usually surrounded by single or double quotes to ensure that they are passed through as a group.
Specifies the location of the ‘postgres’
executable. By default the ‘postgres’ executable is taken from the same
pg_ctl, or failing 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 ‘postgres’ executable was not found. In
initmode, this option analogously specifies the location of the ‘initdb’ executable.
- Only print errors, no informational messages.
- The number of seconds to wait when waiting for start or shutdown to complete.
Wait for the start or shutdown to complete. The default wait time
is 60 seconds. This is the default option for shutdowns. A successful
shutdown is indicated by removal of the PID
file. For starting up, a successful
psql -lindicates success.
pg_ctlwill attempt to use the proper port for psql. If the environment variable
PGPORTexists, that is used. Otherwise, it will see if a port has been set in the ‘postgresql.conf’ file. If neither of those is used, it will use the default port that PostgreSQL was compiled with (5432 by default). When waiting,
pg_ctlwill return an accurate exit code based on the success of the startup or shutdown.
- Do not wait for start or shutdown to complete. This is the default for starts and restarts.
Options for Windows
- Name of the system service to register. The name will be used as both the service name and the display name.
- Password for the user to start the service.
User name for the user to start the service. For domain users, use the
- Default data directory location.
Default host name or Unix-domain socket location for
psql(used by the
Default port number for
psql(used by the
- The existence of this file in the data directory is used to help pg_ctl determine if the server is currently running or not.
If this file exists in the data directory,
restartmode) will pass the contents of the file as options to postgres, unless overridden by the
-ooption. The contents of this file are also displayed in
This file, located in the data directory, is parsed to find the
proper port to use with psql when the
-wis given in
Waiting for complete start is not a well-defined operation and might fail if access control is set up so that a local client cannot connect without manual interaction (e.g., password authentication). For additional connection variables, see Volume 2: Environment Variables, and for passwords, also see Volume 2: The Password File.
Starting the Server
To start up a server:
$ pg_ctl start
An example of starting the server, blocking until the server has come up is:
$ pg_ctl -w start
For a server using port 5433, and
$ pg_ctl -o "-F -p 5433" start
Stopping the Server
$ pg_ctl stop
stops the server. Using the
-m switch allows one
to control how the backend shuts down.
Restarting the Server
Restarting the server is almost equivalent to stopping the
server and starting it again
pg_ctl saves and reuses the command line options that
were passed to the previously running instance. To restart
the server in the simplest form, use:
$ pg_ctl restart
To restart server, 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 the Server Status
Here is a sample status output from pg_ctl:
$ pg_ctl status pg_ctl: server is running (pid: 13718) Command line was: /usr/local/pgsql/bin/postgres '-D' '/usr/local/pgsql/data' '-p' '5433' '-B' '128'
This is the command line that would be invoked in restart mode.
|ISBN 9781906966058||The PostgreSQL 9.0 Reference Manual - Volume 1B - SQL Command Reference||See the print edition|