xenial (1) pg_top.1.gz

Provided by: pgtop_3.7.0-2build1_amd64 bug

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.