postgres.1

PostgreSQL 8.2中增加了很多企业用户所需要的功能和性能上的提高,其开发团队说,该版本将加速更多企业向该数据库移植.核心开发成员之一Bruce Momjian表示,在新版PostgreSQL

\fB-t pa[rser] | pl[anner] | e[xecutor]\fR
Print timing statistics for each query relating to each of the
major system modules. This option cannot be used together
with the \fB-s\fR option.
.TP
\fB-T\fR
This option is for debugging problems that cause a server
process to die abnormally. The ordinary strategy in this
situation is to notify all other server processes that they
must terminate and then reinitialize the shared memory and
semaphores. This is because an errant server process could
have corrupted some shared state before terminating. This
option specifies that \fBpostgres\fR will
stop all other server processes by sending the signal
SIGSTOP, but will not cause them to
terminate. This permits system programmers to collect core
dumps from all server processes by hand.
.TP
\fB-v \fIprotocol\fB\fR
Specifies the version number of the frontend/backend protocol
to be used for a particular session. This option is for
internal use only.
.TP
\fB-W \fIseconds\fB\fR
A delay of this many seconds occurs when a new server process
is started, after it conducts the authentication procedure.
This is intended to give an opportunity to attach to the
server process with a debugger.
.TP
\fB-y \fIdatabase\fB\fR
Indicates that this is a subprocess started by a parent
\fBpostgres\fR process, and specifies the database to
use. This option is for internal use only.
.SS "OPTIONS FOR SINGLE-USER MODE"
.PP
The following options only apply to the single-user mode.
.TP
\fB--single\fR
Selects the single-user mode. This must be the first argument
on the command line.
.TP
\fB\fIdatabase\fB\fR
Specifies the name of the database to be accessed. If it is
omitted it defaults to the user name. 
.TP
\fB-E\fR
Echo all commands.
.TP
\fB-j\fR
Disables use of newline as a statement delimiter.
.TP
\fB-r \fIfilename\fB\fR
Send all server log output to \fIfilename\fR. In normal multiuser
mode, this option is ignored, and \fBstderr\fR is
used by all processes.
.SH "ENVIRONMENT"
.TP
\fBPGCLIENTENCODING\fR
Default character encoding used by clients. (The clients may
override this individually.) This value can also be set in the
configuration file.
.TP
\fBPGDATA\fR
Default data directory location
.TP
\fBPGDATESTYLE\fR
Default value of the datestyle run-time
parameter. (The use of this environment variable is deprecated.)
.TP
\fBPGPORT\fR
Default port (preferably set in the configuration file)
.TP
\fBTZ\fR
Server time zone
.SH "DIAGNOSTICS"
.PP
A failure message mentioning semget or
shmget probably indicates you need to configure your
kernel to provide adequate shared memory and semaphores. For more
discussion see in the documentation. You may be able
to postpone reconfiguring your kernel by decreasing shared_buffers to reduce the shared memory
consumption of PostgreSQL, and/or by reducing
max_connections to reduce the semaphore
consumption.
.PP
A failure message suggesting that another server is already running
should be checked carefully, for example by using the command
.sp
.nf
$ \fBps ax | grep postgres\fR
.sp
.fi
or
.sp
.nf
$ \fBps -ef | grep postgres\fR
.sp
.fi
depending on your system. If you are certain that no conflicting
server is running, you may remove the lock file mentioned in the
message and try again.
.PP
A failure message indicating inability to bind to a port may
indicate that that port is already in use by some
non-PostgreSQL process. You may also
get this error if you terminate \fBpostgres\fR
and immediately restart it using the same port; in this case, you
must simply wait a few seconds until the operating system closes
the port before trying again. Finally, you may get this error if
you specify a port number that your operating system considers to
be reserved. For example, many versions of Unix consider port
numbers under 1024 to be ``trusted'' and only permit
the Unix superuser to access them.
.SH "NOTES"
.PP
If at all possible, \fBdo not\fR use
SIGKILL to kill the main
\fBpostgres\fR server. Doing so will prevent
\fBpostgres\fR from freeing the system
resources (e.g., shared memory and semaphores) that it holds before
terminating. This may cause problems for starting a fresh
\fBpostgres\fR run.
.PP
To terminate the \fBpostgres\fR server normally, the
signals SIGTERM, SIGINT, or
SIGQUIT can be used. The first will wait for
all clients to terminate before quitting, the second will
forcefully disconnect all clients, and the third will quit
immediately without proper shutdown, resulting in a recovery run
during restart. The SIGHUP signal will reload
the server configuration files. It is also possible to send
SIGHUP to an individual server process, but that
is usually not sensible.
.PP
The utility command \fBpg_ctl\fR(1) can be used to
start and shut down the \fBpostgres\fR server
safely and comfortably.
.PP
To cancel a running query, send the SIGINT signal
to the process running that command.
.PP
The \fBpostgres\fR server uses SIGTERM
to tell subordinate server processes to quit normally and
SIGQUIT to terminate without the normal cleanup.
These signals \fBshould not\fR be used by users. It
is also unwise to send SIGKILL to a server
process \(em the main \fBpostgres\fR process will
interpret this as a crash and will force all the sibling processes
to quit as part of its standard crash-recovery procedure.
.SH "BUGS"
.PP
The \fB--\fR options will not work on \fBFreeBSD\fR or \fBOpenBSD\fR.
Use \fB-c\fR instead. This is a bug in the affected operating
systems; a future release of PostgreSQL
will provide a workaround if this is not fixed.
.SH "USAGE"
.PP
To start a single-user mode server, use a command like
.sp
.nf
\fBpostgres --single -D /usr/local/pgsql/data \fIother-options\fB my_database\fR
.sp
.fi
Provide the correct path to the database directory with \fB-D\fR, or
make sure that the environment variable \fBPGDATA\fR is set.
Also specify the name of the particular database you want to work in.
.PP
Normally, the single-user mode server treats newline as the command
entry terminator; there is no intelligence about semicolons,
as there is in \fBpsql\fR. To continue a command
across multiple lines, you must type backslash just before each
newline except the last one.
.PP
But if you use the \fB-j\fR command line switch, then newline does
not terminate command entry. In this case, the server will read the standard input
until the end-of-file (EOF) marker, then
process the input as a single command string. Backslash-newline is not
treated specially in this case.
.PP
To quit the session, type EOF
(\fBControl\fR+\fBD\fR, usually).
If you've
used \fB-j\fR, two consecutive EOFs are needed to exit.
.PP
Note that the single-user mode server does not provide sophisticated
line-editing features (no command history, for example).
.SH "EXAMPLES"
.PP
To start \fBpostgres\fR in the background
using default values, type:
.sp
.nf
$ \fBnohup postgres >logfile 2>&1 </dev/null &\fR
.sp
.fi
.PP
To start \fBpostgres\fR with a specific
port:
.sp
.nf
$ \fBpostgres -p 1234\fR
.sp
.fi
This command will start up \fBpostgres\fR
communicating through the port 1234. In order to connect to this
server using \fBpsql\fR, you would need to run it as
.sp
.nf
$ \fBpsql -p 1234\fR
.sp
.fi
or set the environment variable \fBPGPORT\fR:
.sp
.nf
$ \fBexport PGPORT=1234\fR
$ \fBpsql\fR
.sp
.fi
.PP
Named run-time parameters can be set in either of these styles:
.sp
.nf
$ \fBpostgres -c work_mem=1234\fR
$ \fBpostgres --work-mem=1234\fR
.sp
.fi
Either form overrides whatever setting might exist for
work_mem in \fIpostgresql.conf\fR. Notice that
underscores in parameter names can be written as either underscore
or dash on the command line. Except for short-term experiments,
it's probably better practice to edit the setting in
\fIpostgresql.conf\fR than to rely on a command-line switch
to set a parameter.
.SH "SEE ALSO"
.PP
\fBinitdb\fR(1),
\fBpg_ctl\fR(1)