Provided by: pgtop_3.7.0-18-gbbf1f12-3_amd64 
NAME
pg_top - display and update information about the top cpu PostgreSQL processes
SYNOPSIS
pg_top [ OPTIONS ] [ NUMBER ]
DESCRIPTION
pg_top displays the top processes on the system and periodically updates this information. Raw cpu
percentage is used to rank the processes. If number is given, then the top number processes will be
displayed instead of the default.
pg_top makes a distinction between terminals that support advanced capabilities and those that do not.
This distinction affects the choice of defaults for certain options. In the remainder of this document,
an "intelligent" terminal is one that supports cursor addressing, clear screen, and clear to end of line.
Conversely, a "dumb" terminal is one that does not support such features. If the output of pg_top is
redirected to a file, it acts as if it were being run on a dumb terminal.
OPTIONS
-C, --color-mode
Turn off the use of color in the display.
-I, --hide-idle
Do not display idle processes. By default, pg_top displays both active and idle processes.
-T, --show-tags
List all available color tags and the current set of tests used for color highlighting, then exit.
-W, --password
Forces pg_top to prompt for a password before connecting to a database.
-b, --batch
Use "batch" mode. In this mode, all input from the terminal is ignored. Interrupt characters
(such as ^C and ^\) still have an effect. This is the default on a dumb terminal, or when the
output is not a terminal.
-c, --show-command
Show the command name for each process. Default is to show the full command line. This option is
not supported on all platforms.
-i, --interactive
Use "interactive" mode. In this mode, any input is immediately read for processing. See the
section on "Interactive Mode" for an explanation of which keys perform what functions. After the
command is processed, the screen will immediately be updated, even if the command was not
understood. This mode is the default when standard output is an intelligent terminal.
-n, --non-interactive
Use "non-interactive" mode. This is indentical to "batch" mode.
-q, --quick-mode
Renice pg_top to -20 so that it will run faster. This can be used when the system is being very
sluggish to improve the possibility of discovering the problem. This option can only be used by
root.
-r, --remote-mode
Monitor a remote database where the database is on a system other than where pg_top is running
from. pg_top will monitor a remote database if it has the pg_proctab extension installed.
-u, --show-uid
Do not take the time to map uid numbers to usernames. Normally, pg_top will read as much of the
file "/etc/passwd" as is necessary to map all the user id numbers it encounters into login names.
This option disables all that, while possibly decreasing execution time. The uid numbers are
displayed instead of the names.
-V, --version
Write version number information to stderr then exit immediately. No other processing takes place
when this option is used. To see current revision information while pg_top is running, use the
help command "?".
-s TIME, --set-delay=TIME
TIME Set the delay between screen updates to TIME seconds. The default delay between updates is 5
seconds.
-o FIELD, --order-field=FIELD
Sort the process display area on the specified field. The field name is the name of the column as
seen in the output, but in lower case. Likely values are "cpu", "size", "res", and "time", but
may vary on different operating systems. Note that not all operating systems support this option.
-x COUNT, --set-display=COUNT
Show only count displays, then exit. A display is considered to be one update of the screen.
This option allows the user to select the number of displays he wants to see before pg_top
automatically exits. For intelligent terminals, no upper limit is set. The default is 1 for dumb
terminals.
-z USERNAME, --show-username=USERNAME
Show only those processes owned by USERNAME. This option currently only accepts usernames and
will not understand uid numbers.
-h HOST, --host=HOST
Specifies the host name of the machine on which the server is running. If the value begins with a
slash, it is used as the directory for the Unix domain socket. The default is taken from the
PGHOST environment variable, if set.
-p PORT, --port=PORT
Specifies the TCP port or local Unix domain socket file extension on which the server is listening
for connections. Defaults to the PGPORT environment variable, if set.
-U USERNAME, --username=USERNAME
User name to connect as.
-W, --password
Force pg_top to prompt for a password before connecting to a database.
Both COUNT and NUMBER fields can be specified as "infinite", indicating that they can stretch as far as
possible. This is accomplished by using any proper prefix of the keywords "infinity", "maximum", or
"all". The default for count on an intelligent terminal is, in fact, infinity.
The environment variable PG_TOP is examined for options before the command line is scanned. This enables
a user to set his or her own defaults. The number of processes to display can also be specified in the
environment variable PG_TOP. The options -C, -I, and -u are actually toggles. A second specification of
any of these options will negate the first. Thus a user who has the environment variable PG_TOP set to
"-I" may use the command "top -I" to see idle processes.
INTERACTIVE MODE
When pg_top is running in "interactive mode", it reads commands from the terminal and acts upon them
accordingly. In this mode, the terminal is put in "CBREAK", so that a character will be processed as
soon as it is typed. Almost always, a key will be pressed when pg_top is between displays; that is,
while it is waiting for time seconds to elapse. If this is the case, the command will be processed and
the display will be updated immediately thereafter (reflecting any changes that the command may have
specified). This happens even if the command was incorrect. If a key is pressed while pg_top is in the
middle of updating the display, it will finish the update and then process the command. Some commands
require additional information, and the user will be prompted accordingly. While typing this information
in, the user's erase and kill keys (as set up by the command stty) are recognized, and a newline
terminates the input.
These commands are currently recognized (^L refers to control-L):
^L Redraw the screen.
A Display the actual query plan (EXPLAIN ANALYZE) of the currently running SQL statement by re-
running the SQL statement (prompt for process id.)
C Toggle the use of color in the display.
c Toggle the display of the full command line.
d Change the number of displays to show (prompt for new number). Remember that the next display
counts as one, so typing d1 will make pg_top show one final display and then immediately exit.
h or ? Display a summary of the commands (help screen). Version information is included in this display.
E Display re-determined execution plan (EXPLAIN) of the SQL statement by a backend process (prompt
for process id.)
e Display a list of system errors (if any) generated by the last kill or renice command.
i (or I) Toggle the display of idle processes.
k Send a signal ("kill" by default) to a list of processes. This acts similarly to the command
kill(1)).
L Display the currently held locks by a backend process (prompt for process id.)
M Order by memory utilization.
N Sort by process id.
n or # Change the number of processes to display (prompt for new number).
o Change the order in which the display is sorted. This command is not available on all systems.
The sort key names when viewing processes vary fron system to system but usually include: "cpu",
"res", "size", "time". The default is cpu. When viewing user table statistics: "seq_scan",
"seq_tup_read", "idx_scan", "idx_tup_fetch", "n_tup_ins", "n_tup_upd", "n_tup_del". The default
is seq_scan. When viewing user index statistics: "idx_scan", "idx_tup_fetch", "idx_tup_read".
The default is idx_scan.
P Sort by processor utilization.
Q Display the currently running query of a backend process (prompt for process id.)
q Quit pg_top.
R Display user table statistics.
r Change the priority (the "nice") of a list of processes. This acts similarly to the command
renice(8)).
s Change the number of seconds to delay between displays (prompt for new number).
T Order by time.
t Toggle between cumulative or differential statistics when viewing user table or user index
statistics.
u Display only processes owned by a specific username (prompt for username). If the username
specified is simply "+", then processes belonging to all users will be displayed.
X Display user index statistics.
THE DISPLAY
The actual display varies depending on the specific variant of Unix that the machine is running. This
description may not exactly match what is seen by pg_top running on this particular machine. Differences
are listed at the end of this manual entry.
The top few lines of the display show general information about the state of the system, including the
last process id assigned to a process (on most systems), the three load averages, the current time, the
number of existing processes, the number of processes in each state (sleeping, running, starting,
zombies, and stopped), and a percentage of time spent in each of the processor states (user, nice,
system, and idle). It also includes information about physical and virtual memory allocation.
The remainder of the screen displays information about individual processes. This display is similar in
spirit to ps(1) but it is not exactly the same. The columns displayed by pg_top will differ slightly
between operating systems. Generally, the following fields are displayed:
PID The process id.
USERNAME
Username of the process's owner (if -u is specified, a UID column will be substituted for
USERNAME).
PRI Current priority of the process.
NICE Nice amount in the range -20 to 20, as established by the use of the command nice.
SIZE Total size of the process (text, data, and stack) given in kilobytes.
RES Resident memory: current amount of process memory that resides in physical memory, given in
kilobytes.
STATE Current state (typically one of "sleep", "run", "idl", "zomb", or "stop").
TIME Number of system and user cpu seconds that the process has used.
CPU Percentage of available cpu time used by this process.
COMMAND
Name of the command that the process is currently running.
COLOR
pg_top supports the use of ANSI color in its output. By default, color is available but not used. The
environment variable TOPCOLORS specifies colors to use and conditions for which they should be used. At
the present time, only numbers in the summay display area can be colored. In a future version it will be
possible to highlight numbers in the process display area as well. The environment variable is the only
way to specify color: there is no equivalent command line option. Note that the environment variable
TOPCOLOURS is also understood. The British spelling takes precedence. The use of color only works on
terminals that understand and process ANSI color escape sequences.
The environment variable is a sequence of color specifications, separated by colons. Each specification
takes the form tag=min,max#code where tag is the name of the value to check, min and max specify a range
for the value, and code is an ANSI color code. Multiple color codes can be listed and separated with
semi-colons. A missing min implies the lowest possible value (usually 0) and a missing max implies
infinity. The comma must always be present. When specifying numbers for load averages, they should be
multiplied by 100. For example, the specification 1min=500,1000#31 indicates that a 1 minute load
average between 5 and 10 should be displayed in red. Color attributes can be combined. For example, the
specification 5min=1000,#37;41 indicates that a 5 minute load average higher than 10 should be displayed
with white characters on a red background. A special tag named header is used to control the color of the
header for process display. It should be specified with no lower and upper limits, specifically
header=,# followed by the ANSI color code.
You can see a list of color codes recognized by this installation of pg_top with the -T option. This
will also show the current set of tests used for color highligting, as specified in the environment.
AUTHOR
William LeFebvre Mark Wong
ENVIRONMENT
PG_TOP user-configurable defaults for options. PG_TOPCOLORS color specification
BUGS
As with ps(1), things can change while pg_top is collecting information for an update. The picture it
gives is only a close approximation to reality.
SEE ALSO
kill(1), ps(1), stty(1), mem(4), renice(8)
LINUX NOTES
The Linux port was written by Richard Henderson <rth@tamu.edu>. The CPU% calculation was brazenly stolen
from the Solaris 2 port and should be attributed to one of the many names listed in its man page.
The order support was stolen from SUNOS 5 port by Alexey Klimkin <kad@klon.tme.mcst.ru>
Made to work under 2.4 by William LeFebvre.
PG_TOP(1) Local 4th Berkeley Distribution