POSTGRES(1)						  PostgreSQL Server Applications					       POSTGRES(1)

NAME

       postgres - run a PostgreSQL server in single-user mode

SYNOPSIS

       postgres  [  -A	 0 | 1 ] [ -B nbuffers ] [ -c name=value ] [ -d debug-level ] [ -D datadir ] [ -e ] [ -E ] [ -f  s | i | t | n | m | h ] [
       -F ] [ -i ] [ -N ] [ -o filename ] [ -O ] [ -P ] [ -s | -t  pa | pl | ex ] [ -S sort-mem ] [ -W seconds ] [ --name=value ] database

       postgres [ -A   0 | 1 ] [ -B nbuffers ] [ -c name=value ] [ -d debug-level ] [ -D datadir ] [ -e ] [ -f	s | i | t | n | m | h ] [ -F  ]  [
       -i  ]  [  -o  filename  ]  [ -O ] [ -p database ] [ -P ] [ -s | -t  pa | pl | ex ] [ -S sort-mem ] [ -v protocol-version ] [ -W seconds ] [
       --name=value ]

DESCRIPTION

       The postgres executable is the actual PostgreSQL server process that processes queries. It is normally not called directly; instead a post-
       master(1) multiuser server is started.

       The  second  form  above is how postgres is invoked by the postmaster(1) (only conceptually, since both postmaster and postgres are in fact
       the same program); it should not be invoked directly this way. The first form invokes the server directly in interactive single-user  mode.
       The primary use for this mode is during bootstrapping by initdb(1).  Sometimes it is used for debugging or disaster recovery.

       When  invoked  in  interactive mode from the shell, the user can enter queries and the results will be printed to the screen, but in a form
       that is more useful for developers than end users. But note that running a single-user backend is not  truly  suitable  for  debugging  the
       server since no realistic interprocess communication and locking will happen.

       When  running  a  stand-alone  backend, the session user will be set to the user with ID 1. This user does not actually have to exist, so a
       stand-alone backend can be used to manually recover from certain kinds of accidental damage to the system catalogs. Implicit superuser pow-
       ers are granted to the user with ID 1 in stand-alone mode.

OPTIONS

       When  postgres is started by a postmaster(1) then it inherits all options set by the latter. Additionally, postgres-specific options can be
       passed from the postmaster with the -o switch.

       You can avoid having to type these options by setting up a configuration file. See the  Administrator's	Guide  for  details.  Some  (safe)
       options	can also be set from the connecting client in an application-dependent way.  For example, if the environment variable PGOPTIONS is
       set, then libpq-based clients will pass that string to the server, which will interpret it as postgres command-line options.

   GENERAL PURPOSE
       The options -A, -B, -c, -d, -D, -F, and --name have the same meanings as the postmaster(1) except that -d 0 prevents the debugging level of
       the postmaster from being propagated to the backend.

       -e     Sets  the  default date style to ``European'', which means that the ``day before month'' (rather than month before day) rule is used
	      to interpret ambiguous date input, and that the day is printed before the month in certain date output formats. See  the	PostgreSQL
	      User's Guide for more information.

       -o filename
	      Sends  all  debugging and error output to filename.  If the backend is running under the postmaster, this option is ignored, and the
	      stderr inherited from the postmaster is used.

       -P     Ignore system indexes while scanning/updating system tuples. The REINDEX command for system tables/indexes requires this	option	to
	      be used.

       -s     Print time information and other statistics at the end of each query.  This is useful for benchmarking or for use in tuning the num-
	      ber of buffers.

       -S sort-mem
	      Specifies the amount of memory to be used by internal sorts and hashes before resorting to temporary disk files. The value is speci-
	      fied  in	kilobytes,  and  defaults to 512 kilobytes. Note that for a complex query, several sorts and/or hashes might be running in
	      parallel, and each one will be allowed to use as much as sort-mem kilobytes before it starts to put data into temporary files.

   OPTIONS FOR STAND-ALONE MODE
       database
	      Specifies the name of the database to be accessed. If it is omitted it defaults to the user name.

       -E     Echo all queries.

       -N     Disables use of newline as a query delimiter.

   SEMI-INTERNAL OPTIONS
       There are several other options that may be specified, used mainly for debugging purposes. These are listed here only for the use by  Post-
       greSQL system developers. Use of any of these options is highly discouraged. Furthermore, any of these options may disappear or change in a
       future release without notice.

       -f { s | i | m | n | h }
	      Forbids the use of particular scan and join methods: s and i disable sequential and index scans respectively, while n, m, and h dis-
	      able nested-loop, merge and hash joins respectively.

	      Note: Neither sequential scans nor nested-loop joins can be disabled completely; the -fs and -fn options simply discourage the opti-
	      mizer from using those plan types if it has any other alternative.

       -i     Prevents query execution, but shows the plan tree.

       -O     Allows the structure of system tables to be modified. This is used by initdb.

       -p database
	      Indicates that this server has been started by a postmaster and makes different  assumptions  about  buffer  pool  management,  file
	      descriptors, etc.

       -t pa[rser] | pl[anner] | e[xecutor]
	      Print timing statistics for each query relating to each of the major system modules. This option cannot be used together with the -s
	      option.

       -v protocol
	      Specifies the version number of the frontend/backend protocol to be used for this particular session.

       -W seconds
	      As soon as this option is encountered, the process sleeps for the specified amount of seconds. This gives developers time to  attach
	      a debugger to the backend process.

ENVIRONMENT

       PGDATA Default data direction location

       For others, which have little influence during single-user mode, see postmaster(1).

NOTES

       To stop a running query use the SIGINT signal. To tell postgres to reread the config file, use a SIGHUP signal. The postmaster uses SIGTERM
       to tell a postgres process to quit normally and SIGQUIT to terminate without the normal cleanup.  These should not be used by users.

USAGE

       Start a stand-alone backend with a command like

       postgres -D $PGDATA other-options my_database

       Provide the correct path to the database area with -D, or make sure that the environment variable PGDATA is set.  Also specify the name	of
       the particular database you want to work in.

       Normally, the stand-alone backend treats newline as the command entry terminator; there is no intelligence about semicolons, as there is in
       psql. To continue a command across multiple lines, you must type backslash just before each newline except the last one.

       But if you use the -N command line switch, then newline does not terminate command entry. The backend will read the  standard  input  until
       the end-of-file (EOF) marker, then process the input as a single query string. Backslash-newline is not treated specially in this case.

       To quit the session, type EOF (Control+D, usually).  If you've used -N, two consecutive EOFs are needed to exit.

       Note that the stand-alone backend does not provide sophisticated line-editing features (no command history, for example).

SEE ALSO

       initdb(1), ipcclean(1), postmaster(1)

Application							    2002-11-22							       POSTGRES(1)