pg_ctl

Name

pg_ctl -- Starts, stops, and restarts postmaster

pg_ctl [-w] [-D datadir ][-p path ] [-o "options "] start

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

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

pg_ctl [-D datadir ] status

Inputs

-w

Wait for the database server to come up, by watching for creation of the pid file (PGDATA/postmaster.pid). Times out after 60 seconds.

-D datadir

Specifies the database location for this database installation.

-p path

Specifies the path to the postmaster image.

-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.

-m mode

Specifies the shutdown mode.

smart, s

smart mode waits for all the clients to logout. This is the default.

fast, f

Fast mode sends SIGTERM to the backends; that means active transactions get rolled back.

immediate, i

Immediate mode sends SIGUSR1 to the backends and lets them abort. In this case, database recovery will be necessary on the next start-up.

start

Start up postmaster.

stop

Shut down postmaster.

restart

Restart the postmaster, performing a stop/start sequence.

status

Show the current state of postmaster.

Outputs

pg_ctl: postmaster is state (pid: # )

Postmaster status.

If there is an error condition, the backend error message will be displayed.

Description

pg_ctl is a utility for starting, stopping or restarting postmaster.

Usage

Starting postmaster

To start up postmaster:

 

        $ pg_ctl start  

If -w is supplied, pg_ctl waits for the database server to come up, by watching for creation of the pid file (PGDATA/postmaster.pid), for up to 60 seconds.

Parameters to invoke postmaster are taken from the following sources:

• Path to postmaster: found in the command search path.
• Database directory: PGDATA environment variable.
• Other parameters: PGDATA/postmaster.opts.default.

postmaster.opts.default contains parameters for postmaster.

Note that postmaster.opts.default is installed by initdb from lib/postmaster.opts.default.sample under the Postgres installation directory (lib/postmaster.opts.default.sample is copied from src/bin/pg_ctl/postmaster.opts.default.sample while installing Postgres).

To override the default parameters you can use -D, -p and -o options.

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

 

        $ pg_ctl -w start  

To specify the postmaster binary path, try:

 

        $ pg_ctl -p /usr/local/pgsql/bin/postmaster start  

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

 

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

Stopping postmaster

$ pg_ctl stop stops postmaster. Using the -m switch allows one to control how the backend shuts down. -w waits for postmaster to shut down. -m specifies the shut down mode.

Restarting postmaster

This is almost equivalent to stopping the postmaster then starting it again except that the parameters used before stopping it would be used too. This is done by saving them in $PGDATA/postmaster.opts file. -w, -D, -m, -fast, -immediate and -o can also be used in the restarting mode and they have the same meanings as described above.

To restart 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 "-o -F -p 5433" restart   

postmaster status

To get status information from postmaster:

 

        $ pg_ctl status  

Here is a sample output from pg_ctl:

 

        pg_ctl: postmaster is running (pid: 13718)
        options are:
        /usr/local/src/pgsql/current/bin/postmaster
        -p 5433
        -D /usr/local/src/pgsql/current/data
        -B 64
        -b /usr/local/src/pgsql/current/bin/postgres
        -N 32
        -o '-F'