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doc/src/sgml/ref/postgres-ref.sgml

+.\" This is -*-nroff-*-
+.\" XXX standard disclaimer belongs here....
+.\" $Header: /cvsroot/pgsql/doc/src/sgml/ref/postgres-ref.sgml,v 1.1 1999/05/26 17:25:38 thomas Exp $
+.TH POSTGRESQL UNIX 05/19/99 PostgreSQL PostgreSQL
+.SH NAME
+postgres - the Postgres backend server
+.SH SYNOPSIS
+.BR "postgres"
+[\c
+.BR "-B"
+n_buffers]
+[\c
+.BR "-C"
+]
+[\c
+.BR "-D"
+data_directory]
+[\c
+.BR "-E"
+]
+[\c
+.BR "-F"
+]
+[\c
+.BR "-O"
+]
+[\c
+.BR "-Q"
+]
+[\c
+.BR "-S kbytes"
+]
+[\c
+.BR "-d"
+debug_level]
+[\c
+.BR "-e"
+]
+[\c
+.BR "-o"
+output_file]
+[\c
+.BR "-s"
+]
+[\c
+.BR "-v protocol"
+]
+[dbname]
+.in -5n
+.SH DESCRIPTION
+The Postgres backend server can be executed directly from the user shell.
+This should be done only while debugging by the DBA, and should not be
+done while other Postgres backends are being managed by a
+.IR postmaster
+on this set of databases.
+.PP
+Some of the switches explained in this man page can be passed to the backend
+through the "database options" field of a connection request, and thus can be
+set for a particular backend without going to the trouble of restarting the
+postmaster.  This is particularly handy for debugging-related switches.
+.PP
+The optional argument
+.IR dbname
+specifies the name of the database to be accessed.
+.IR Dbname
+defaults to the value of the
+.SM USER
+environment variable.
+.PP
+The 
+.IR postgres
+server understands the following command-line options:
+.TP
+.BR "-B" " n_buffers"
+If the backend is running under the 
+.IR postmaster ,
+.IR "n_buffers"
+is the number of shared-memory buffers that the
+.IR "postmaster"
+has allocated for the backend server processes that it starts.  If the
+backend is running standalone, this specifies the number of buffers to
+allocate.  This value defaults to 64 buffers, where each buffer is 8k bytes
+(or whatever BLCKSZ is set to in config.h).
+.TP
+.BR "-C"
+Do not show server version number.
+.TP
+.BR "-D" " data_directory"
+This option specifies the pathname of the directory that contains the
+database system data (the tables, the catalogs, etc.).  If you don't 
+specify this option, Postgres uses the value of the PGDATA environment
+variable.  You must either specify a -D option or set PGDATA.
+ 
+The data directory pathname for a database system is normally determined when
+the database system is created with
+.IR initdb ,
+with a --pgdata option to
+.IR initdb .
+.TP
+.BR "-E"
+Echo all queries.
+.TP
+.BR "-F"
+Disable automatic fsync() call after each transaction.
+This option improves performance, but an operating system crash
+while a transaction is in progress will probably cause data loss.
+.TP
+.BR "-O"
+Override restrictions, so system table structures can be modified(pg_*).
+.TP
+.BR "-Q"
+Specifies \*(lqquiet\*(rq mode.
+.TP
+.BR "-S" " kbytes"
+Specifies the amount of memory to be used by internal sorts and hashes
+before resorting to temporary disk files.  The value is specified 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 -S kilobytes before it starts to put
+data into temporary files.
+.TP
+.BR "-e"
+The
+.IR "-e"
+option controls how dates are input to and output from the database.
+.IP
+If the
+.IR "-e"
+option is supplied, then all dates passed to and from the frontend
+processes will be assumed to be in
+.IR "European"
+format ie.
+.IR "DD-MM-YYYY"
+otherwise dates are input and output in
+.IR "American"
+format ie.
+.IR "MM-DD-YYYY"
+.TP
+.BR "-d" " debug_level"
+Turns on debugging at the numeric level
+.IR "debug_level" .
+Turning on debugging will cause query, parse trees, and query plans to
+be displayed.
+.TP
+.BR "-o" " output_file"
+Sends all debugging and error output to 
+.IR output_file .
+If the backend is running under the 
+.IR postmaster ,
+error messages are still sent to the frontend process as well as to
+.IR output_file ,
+but debugging output is sent to the controlling tty of the
+.IR postmaster
+(since only one file descriptor can be sent to an actual file).
+.TP
+.BR "-s"
+Print time information and other statistics at the end of each query.
+This is useful for benchmarking or for use in tuning the number of
+buffers.
+.TP
+.BR "-v" " protocol"
+Specifies the number of the frontend/backend protocol to be used for this
+particular session.
+.SH "DEVELOPER COMMAND OPTIONS"
+There are several other options that may be specified, used mainly
+for debugging purposes.  These are listed here only for the use by
+Postgres system developers.
+.BR "Use of any of these options is highly discouraged" .
+Furthermore, any of these options may disappear or change at any time.
+.TP
+.BR "-A" "n|r|b|Q\fIn\fP|X\fIn\fP"
+.IP
+This option generates a tremendous amount of output.
+.TP
+.BR "-L"
+Turns off the locking system.
+.TP
+.BR "-N"
+Disables use of newline as a query delimiter.
+.TP
+.BR "-f"
+Forbids the use of particular scan and join methods:
+.IR s " and " i
+disable sequential and index scans respectively, while
+.IR n ", " m " and " h
+disable nested-loop, merge and hash joins respectively.
+(Neither sequential scans nor nested-loop joins can be disabled completely;
+the -fs and -fn options simply discourage the optimizer from using those
+plan types if it has any other alternative.)
+.TP
+.BR "-i"
+Prevents query execution, but shows the plan tree.
+.TP
+.BR "-p" " databasename"
+Indicates to the backend server that it has been started by a 
+.IR postmaster
+and make different assumptions about buffer pool management, file
+descriptors, etc.  Switches following -p are restricted to those
+considered "secure".
+.TP
+.BR "-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 with
+.BR "-s" .
+.SH "SEE ALSO"
+ipcclean(1),
+psql(1), 
+postmaster(1).
+.SH "DIAGNOSTICS"
+Of the nigh-infinite number of error messages you may see when you
+execute the backend server directly, the most common will probably be:
+.TP
+.BR "semget: No space left on device"
+If you see this message, you should run the
+.IR ipcclean
+command.  After doing this, try starting
+.IR postgres
+again.  If this still doesn't work, you probably need to configure
+your kernel for shared memory and semaphores as described in the
+installation notes.