Re: [HACKERS] pg_ctl man page

I got grammer corrections from Ed Loehr. Also, I modified some option
flag styles according to Thomas's suggestion. Thanks for those who
gave me suggestions.

Thomas, I have changed -m <opts> style to -smart, -fast... style. I
hope this was what you meant. Also, please note that I still stick
with smart/fast/immediate since I have been waiting for Vadim's
opinion...

Tatsuo Ishii
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NAME

pg_ctl - starts/stops/restarts postmaster

SYNOPSIS

pg_ctl [-w][-D database_dir][-p path_to_postmaster][-o "postmaster_opts"] start
pg_ctl [-w][-D database_dir][-smart|-fast|-immediate] stop
pg_ctl [-w][-D database_dir][-smart|-fast|-immediate][-o "postmaster_opts"] restart
pg_ctl [-D database_dir] status

DESCRIPTION

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

Starting postmaster

To start postmaster:

pg_ctl start

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

Parameters to invoke postmaster are taken from 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. With a
default installation, the "-S" option is enabled. So "pg_ctl start"
implies:

postmaster -S

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

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

-D database_dirspecifies the database directory

-p path_to_postmasterspecifies the path to postmaster

-o "postmaster_opts"specifies any parameters for postmaster

Examples:

# blocks until postmaster comes up
pg_ctl -w start

# specifies postmaster path
pg_ctl -p /usr/local/pgsq/bin/postmaster start

# uses port 5433 and disables fsync
pg_ctl -o "-o -F -p 5433" start

Stopping postmaster

pg_ctl stop

stops postmaster.

There are several options for the stopping mode.

-wwaits for postmaster to shut down

-smart|-fast|-immediate      specifies the shutdown mode. smart mode waits for all      the clients to logout. This is
thedefault.      fast mode sends SIGTERM to the backends, that means      active transactions get rolled back.
immediatemode sends SIGUSR1      to the backends and lets them abort. In this case, database recovery      will be
neccessaryon the next startup.
 


Restarting postmaster

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

Examples:

# restarts postmaster in the simplest form
pg_ctl restart

# restarts postmaster, waiting for it to shut down and to come up
pg_ctl -w restart

# uses port 5433 and disables fsync next time
pg_ctl -o "-o -F -p 5433" restart

Getting status from postmaster

To get status information from postmaster:

pg_ctl status

Following is sample outputs 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'


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