The Performance Monitor dynamically samples activity statistics
on a database. You can display the statistics at your terminal
and can also write them to a formatted binary file.
The statistics show activity only from the node on which you
execute the command.
The Performance Monitor operates in one of three modes: online,
record, and replay. In online mode, you can display or record
current activity on a database. In record mode, you can record
statistics in a binary file. In replay mode, you can examine a
previously recorded binary statistics file.
If you use the Input qualifier, the Performance Monitor executes
in replay mode. In replay mode, this command generates an
interactive display from a previously recorded binary statistics
file.
If you do not use the Input qualifier, you must specify a
database file name. The Performance Monitor then executes in
online mode. In online mode, the command generates an interactive
display when you use the Interactive qualifier and can also
record statistics in a binary file.
The interactive display is made up of numerous output pages.
You control the interactive display by means of menus, arrow
keys, and the Return key to select options. You select an item
by pressing the arrow keys until the desired item is highlighted,
then press the Return key.
Display the Select Display options (by typing D) from the
Performance Monitor screen to view the available output pages.
Items in the Display menu followed by this set of characters:
[->, indicate that a submenu is displayed when you select this
item.
Once you have selected a display, there are a number of methods
you can use to navigate through the screens:
o To move to the next screen of information, do one of the
following:
- Press the right arrow (- > ) keyboard key.
- Press the Next Screen keyboard key.
o To move to the previous screen of information, do one of the
following:
- Press the left arrow (< - ) keyboard key.
- Press the Prev Screen keyboard key.
o To move forward n number of screens, press the plus (+)
keyboard key and enter the value n.
o To move backward n number of screens, press the minus (-)
keyboard key and enter the value n.
o To move directly from the first screen to the last screen, do
one of the following:
- Press the up arrow (^ ) keyboard key.
- Press the plus (+) keyboard key and enter the value 0.
o To move directly from the last screen to the first screen, do
one of the following:
- Press the down arrow (v ) keyboard key.
- Press the hyphen (-) keyboard key and enter the value 0.
o To quickly locate a screen in the current submenu group that
contains activity, press the space bar on your keyboard.
This feature works even when you are replaying a binary input
file. If there is no screen in the current subgroup that has
activity, the next screen is displayed (as though you had
used the Next Screen key). The Performance Monitor ignores
computational screens, such as Stall Messages, Monitor Log,
and so on, when searching for activity.
In interactive mode, enter an exclamation point to open the
Select Tool menu. This menu allows you to switch the database
for which you are displaying statistics, edit a file, invoke a
system command, and so on. (The ability to open a new database
is not available if you specify the Input or Output qualifier.)
In addition, it provides you the ability to locate a specific
statistics screen either by name (or portion thereof) or by a
summary-selection menu. Select the Goto screen or Goto screen
"by-name" options from the Select Tool menu to use these options.
In interactive mode, you can pause output scrolling on your
screen by pressing the P key. Resume output scrolling by pressing
the P key again.
An extensive online help facility for the character-cell
interface is available by doing the following from the
Performance Monitor screen:
1. Type H or PF2.
2. Select the type of help you want (keyboard, screen, or field).
3. Press the Return key.
If you select field level help, you must also do the following:
1. Highlight the field for which you want help information.
2. Press the Return key.
All screens regardless of format or display contents have a
standard format as follows:
o First line
Contains the node name, the utility name and version number,
and the current system date and time. The current system date
and time are updated at the specified set-rate interval.
o Second line
Contains the screen refresh rate, in seconds; the current
screen name; and the elapsed time since the last set-rate
command, which indicates how long the screen information has
been collected.
o Third line
Contains the current page number within the screen (screen X
of Y), the name of the current database, and the statistics
utility operation mode (online, record, or replay). Online
mode is the normal database activity displayed in real
time. Record mode indicates that the database activity being
displayed is being recorded to an external file specified by
the Output qualifier. Replay mode indicates that the database
activity is being displayed from the external file specified
by the Input qualifier.
You can display most statistics in either a histogram or a
columnar chart, although several display pages have special
formats. By default, the initial interactive display appears
in histogram mode; by using the Nohistogram qualifier, you can
direct Oracle RMU to display statistics in tabular numeric mode.
In addition, you can produce time-plot graphics for individual
statistical fields.
Use the Output qualifier to direct statistical output to a file.
The output is a formatted binary file and does not produce a
legible printed listing. To read the output, you must use the RMU
Show Statistics command with the Input qualifier.
The Nointeractive qualifier suppresses the interactive display.
Use this qualifier when you want to generate binary statistics
output but do not want an online display.
Database statistics are maintained in a global section on each
system on which Oracle Rdb is running. Statistics are reset to
zero when you close a database. Running the Performance Monitor
keeps the database open even when there are no users accessing
the database.
The Stall Messages display permits you to display multiple
screens of information. Access the Stall Messages display by
selecting Per-Process Information from the Select Display Menu;
then select the Stall Messages display from the secondary menu.
If you are displaying the last screen of Stall Messages
information and the number of stalled processes is reduced such
that the last screen is empty, you are automatically moved to the
newest last screen of information when you press the Next Screen
keyboard key (or the right arrow keyboard key).
You can also use the Alarm, Notify, and Screen qualifiers to
simplify monitoring stalled processes. See the description of
each of these qualifiers for more information.