.\\" auto-generated by docbook2man-spec $Revision: 1.25 $
.TH "PG_CTL" "1" "2002-11-22" "Application" "PostgreSQL Server Applications"
.SH NAME
pg_ctl \- start, stop, or restart a PostgreSQL server
.SH SYNOPSIS
.sp
\fBpg_ctl\fR \fBstart\fR\fR [ \fR\fB-w \fR\fR]\fR\fR [ \fR\fB-s \fR\fR]\fR\fR [ \fR\fB-D \fIdatadir\fB \fR\fR]\fR\fR [ \fR\fB-l \fIfilename\fB \fR\fR]\fR\fR [ \fR\fB-o \fIoptions\fB \fR\fR]\fR\fR [ \fR\fB-p \fIpath\fB \fR\fR]\fR

\fBpg_ctl\fR \fBstop\fR\fR [ \fR\fB-W \fR\fR]\fR\fR [ \fR\fB-s \fR\fR]\fR\fR [ \fR\fB-D \fIdatadir\fB \fR\fR]\fR\fR [ \fR\fB-m \fR\fB s[mart]\fR | \fBf[ast]\fR | \fBi[mmediate]\fR\fB \fR\fR]\fR

\fBpg_ctl\fR \fBrestart\fR\fR [ \fR\fB-w \fR\fR]\fR\fR [ \fR\fB-s \fR\fR]\fR\fR [ \fR\fB-D \fIdatadir\fB \fR\fR]\fR\fR [ \fR\fB-m \fR\fB s[mart]\fR | \fBf[ast]\fR | \fBi[mmediate]\fR\fB \fR\fR]\fR\fR [ \fR\fB-o \fIoptions\fB \fR\fR]\fR

\fBpg_ctl\fR \fBreload\fR\fR [ \fR\fB-s \fR\fR]\fR\fR [ \fR\fB-D \fIdatadir\fB \fR\fR]\fR

\fBpg_ctl\fR \fBstatus\fR\fR [ \fR\fB-D \fIdatadir\fB \fR\fR]\fR
.SH "DESCRIPTION"
.PP
\fBpg_ctl\fR is a utility for starting,
stopping, or restarting \fBpostmaster\fR(1), the
PostgreSQL backend server, or displaying
the status of a running postmaster. Although the postmaster can be
started manually, \fBpg_ctl\fR encapsulates
tasks such as redirecting log output, properly detaching from the
terminal and process group, and it provides convenient options for
controlled shutdown.
.PP
In \fBstart\fR mode, a new postmaster is launched. The
server is started in the background, the standard input attached to
\fI/dev/null\fR. The standard output and standard
error are either appended to a log file, if the \fB-l\fR
option is used, or are redirected to
\fBpg_ctl\fR's standard output (not standard
error). If no log file is chosen, the standard output of
\fBpg_ctl\fR 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.
.PP
In \fBstop\fR mode, the postmaster that is running in
the specified data directory is shut down. Three different
shutdown methods can be selected with the \fB-m\fR
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.
.PP
\fBrestart\fR mode effectively executes a stop followed
by a start. This allows the changing of postmaster command line
options.
.PP
\fBreload\fR mode simply sends the postmaster a \fBSIGHUP\fR signal,
causing it to reread its configuration files
(\fIpostgresql.conf\fR, \fIpg_hba.conf\fR,
etc.). This allows changing of configuration-file options that do not
require a complete restart to take effect.
.PP
\fBstatus\fR mode checks whether a postmaster is running
and if so displays the PID and the command line
options that were used to invoke it.
.SH "OPTIONS"
.PP
.TP
\fB-D \fIdatadir\fB\fR
Specifies the file system location of the database files. If
this is omitted, the environment variable
\fBPGDATA\fR is used.
.TP
\fB-l \fIfilename\fB\fR
Append the server log output to
\fIfilename\fR. If the file does not
exist, it is created. The \fBumask\fR is set to 077, so access to
the log file from other users is disallowed by default.
.TP
\fB-m \fImode\fB\fR
Specifies the shutdown mode. \fImode\fR
may be smart, fast, or
immediate, or the first letter of one of
these three.
.TP
\fB-o \fIoptions\fB\fR
Specifies options to be passed directly to
\fBpostmaster\fR.

The parameters are usually surrounded by single or double
quotes to ensure that they are passed through as a group.
.TP
\fB-p \fIpath\fB\fR
Specifies the location of the \fIpostmaster\fR
executable. By default the postmaster is taken from the same
directory as \fBpg_ctl\fR, 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 postmaster was not found.
.TP
\fB-s\fR
Only print errors, no informational messages.
.TP
\fB-w\fR
Wait for the start or shutdown to complete. Times out after
60 seconds. This is the default for shutdowns.
.TP
\fB-W\fR
Do not wait for start or shutdown to complete. This is the
default for starts and restarts.
.PP
.SH "ENVIRONMENT"
.TP
\fBPGDATA\fR
Default data direction location
.PP
For others, see \fBpostmaster\fR(1).
.PP
.SH "FILES"
.PP
If the file \fIpostmaster.opts.default\fR exists in
the data directory, the contents of the file will be passed as
options to the \fBpostmaster\fR, unless
overridden by the \fB-o\fR option.
.SH "NOTES"
.PP
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.
.SH "EXAMPLES"
.SS "STARTING THE POSTMASTER"
.PP
To start up a \fBpostmaster\fR:
.sp
.nf
$ \fBpg_ctl start\fR
.sp
.fi
.PP
An example of starting the \fBpostmaster\fR,
blocking until the postmaster comes up is:
.sp
.nf
$ \fBpg_ctl -w start\fR
.sp
.fi
.PP
For a \fBpostmaster\fR using port 5433, and
running without \fBfsync\fR, use:
.sp
.nf
$ \fBpg_ctl -o "-F -p 5433" start\fR
.sp
.fi
.SS "STOPPING THE POSTMASTER"
.PP
.sp
.nf
$ \fBpg_ctl stop\fR
.sp
.fi
stops the postmaster. Using the \fB-m\fR switch allows one
to control \fBhow\fR the backend shuts down.
.SS "RESTARTING THE POSTMASTER"
.PP
This is almost equivalent to stopping the
\fBpostmaster\fR and starting it again
except that \fBpg_ctl\fR saves and reuses the command line options that
were passed to the previously running instance. To restart
the \fBpostmaster\fR in the simplest form:
.sp
.nf
$ \fBpg_ctl restart\fR
.sp
.fi
.PP
To restart \fBpostmaster\fR,
waiting for it to shut down and to come up:
.sp
.nf
$ \fBpg_ctl -w restart\fR
.sp
.fi
.PP
To restart using port 5433 and disabling \fBfsync\fR after restarting:
.sp
.nf
$ \fBpg_ctl -o "-F -p 5433" restart\fR
.sp
.fi
.SS "SHOWING POSTMASTER STATUS"
.PP
Here is a sample status output from
\fBpg_ctl\fR:
.sp
.nf
$ \fBpg_ctl status\fR
pg_ctl: postmaster is running (pid: 13718)
Command line was:
/usr/local/pgsql/bin/postmaster '-D' '/usr/local/pgsql/data' '-p' '5433' '-B' '128'
.sp
.fi
This is the command line that would be invoked in restart mode.
.SH "SEE ALSO"
.PP
\fBpostmaster\fR(1), \fIPostgreSQL Administrator's Guide\fR