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172 lines
4.7 KiB
Groff
172 lines
4.7 KiB
Groff
.\" This is -*-nroff-*-
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.\" XXX standard disclaimer belongs here....
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.\" $Header: /cvsroot/pgsql/doc/man/Attic/postgres.1,v 1.2 1996/09/26 16:49:09 momjian Exp $
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.TH POSTGRES95 UNIX 11/05/95 Postgres95 Postgres95
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.SH NAME
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postgres \(em the Postgres backend server
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.SH SYNOPSIS
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.BR "postgres"
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[\c
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.BR "-B"
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n_buffers]
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[\c
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.BR "-E"
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]
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[\c
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.BR "-F"
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]
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[\c
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.BR "-P"
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filedes]
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[\c
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.BR "-Q"
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]
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.br
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.in +5n
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[\c
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.BR "-d"
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debug_level]
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[\c
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.BR "-o"
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output_file]
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[\c
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.BR "-s"
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]
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[dbname]
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.in -5n
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.SH DESCRIPTION
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The Postgres backend server can be executed directly from the user shell.
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This should be done only while debugging by the DBA, and should not be
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done while other Postgres backends are being managed by a
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.IR postmaster
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on this set of databases.
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.PP
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The optional argument
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.IR dbname
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specifies the name of the database to be accessed.
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.IR Dbname
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defaults to the value of the
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.SM USER
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environment variable.
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.PP
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The
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.IR postgres
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server understands the following command-line options:
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.TP 5n
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.BR "-B" " n_buffers"
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If the backend is running under the
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.IR postmaster ,
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.IR "n_buffers"
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is the number of shared-memory buffers that the
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.IR "postmaster"
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has allocated for the backend server processes that it starts. If the
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backend is running standalone, this specifies the number of buffers to
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allocate. This value defaults to 64.
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.TP
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.BR "-E"
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Echo all queries.
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.TP
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.BR "-F"
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Disbable automatic fsync() call after each transaction.
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This option improves performance, but an operating system crash
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while a transaction is in progress will probably cause data loss.
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.TP
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.BR "-P" " filedes"
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.IR "filedes"
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specifies the file descriptor that corresponds to the socket (port) on
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which to communicate to the frontend process. This option is
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.BR not
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useful for interactive use.
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.TP
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.BR "-Q"
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Specifies \*(lqquiet\*(rq mode.
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.TP
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.BR "-d" " debug_level"
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Turns on debugging at the numeric level
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.IR "debug_level" .
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Turning on debugging will cause query parse trees and query plans to
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be displayed.
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.TP
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.BR "-o" " output_file"
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Sends all debugging and error output to
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.IR output_file .
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If the backend is running under the
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.IR postmaster ,
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error messages are still sent to the frontend process as well as to
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.IR output_file ,
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but debugging output is sent to the controlling tty of the
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.IR postmaster
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(since only one file descriptor can be sent to an actual file).
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.TP
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.BR "-s"
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Print time information and other statistics at the end of each query.
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This is useful for benchmarking or for use in tuning the number of
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buffers.
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.SH "DEPRECATED COMMAND OPTIONS"
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There are several other options that may be specified, used mainly
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for debugging purposes. These are listed here only for the use by
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Postgres system developers.
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.BR "Use of any of these options is highly discouraged" .
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Furthermore, any of these options may disappear or change at any time.
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.TP
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.BR "-A" "n|r|b|Q\fIn\fP|X\fIn\fP"
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.IP
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This option generates a tremendous amount of output.
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.TP
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.BR "-L"
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Turns off the locking system.
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.TP
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.BR "-N"
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Disables use of newline as a query delimiter.
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.TP
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.BR "-S"
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Indicates that the transaction system can run with the assumption of
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stable main memory, thereby avoiding the necessary flushing of data
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and log pages to disk at the end of each transaction system. This is
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only used for performance comparisons for stable vs. non-stable
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storage. Do not use this in other cases, as recovery after a system
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crash may be impossible when this option is specified in the absence
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of stable main memory.
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.TP
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.BR "-b"
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Enables generation of bushy query plan trees (as opposed to left-deep
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query plans trees). These query plans are not intended for actual
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execution; in addition, this flag often causes Postgres to run out of
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memory.
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.TP
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.BR "-f"
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Forbids the use of particular scan and join methods:
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.IR s " and " i
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disable sequential and index scans respectively, while
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.IR n ", " m " and " h
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disable nested-loop, merge and hash joins respectively.
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This is another feature that may not necessarily produce executable
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plans.
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.TP
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.BR "-p"
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Indicates to the backend server that it has been started by a
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.IR postmaster
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and make different assumptions about buffer pool management, file
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descriptors, etc.
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.TP
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.BR "-t" "pa[rser]|pl[anner]|e[xecutor]"
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Print timing statistics for each query relating to each of the major
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system modules. This option cannot be used with
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.BR "-s" .
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.SH "SEE ALSO"
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ipcclean(1),
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psql(1),
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postmaster(1).
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.SH "DIAGNOSTICS"
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Of the nigh-infinite number of error messages you may see when you
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execute the backend server directly, the most common will probably be:
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.TP
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.BR "semget: No space left on device"
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If you see this message, you should run the
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.IR ipcclean
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command. After doing this, try starting
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.IR postgres
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again. If this still doesn't work, you probably need to configure
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your kernel for shared memory and semaphores as described in the
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installation notes.
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