Load Screen [ ALLBASE/SQL Performance and Monitoring Guidelines ] MPE/iX 5.0 Documentation
ALLBASE/SQL Performance and Monitoring Guidelines
Load Screen
This screen provides information useful in measuring the transaction
throughput efficiency of the DBEnvironment.
Click here to view figure.
To invoke the Load screen, use the l command from the Load subsystem or
the /loa command from other subsystems.
When you issue the SET DBENVIRONMENT command, the counters on this screen
are set to zero. See the section "Display Conventions" on the next page
for a description of the CUR, AVG, and MAX headings.
Field Definitions
REFRESH The screen refresh rate, in seconds.
SESSIONS The number of DBEnvironment sessions.
MAX XACT The maximum number of transactions. The maximum number
that may be active at one time appears at the far right
of the scale. The first three numbers on the scale are
1/4, 1/2, and 3/4 of the maximum.
ACTIVE XACT The number of transactions that have started but have
not terminated (that is, a BEGIN WORK statement has
completed, but a COMMIT WORK statement has not yet
begun).
IMPEDE XACT The number of active transactions blocked because they
are
waiting for a lock owned by another session. Compare
the IMPEDE XACT value with the ACTIVE XACT and SESSIONS
values to determine the amount of lock contention.
THROTTLE WT The number of sessions that are waiting for their BEGIN
WORK statements to complete. These sessions are in the
throttle wait queue.
per sec The scale used to identify the length of the inverse
video bars and the data in the CUR, AVG, and MAX
columns. In the above example, the MAX frequency of
LOCK REQSTS is 40 per 1.0 second.
BEGIN WORK The number of BEGIN WORK commands being processed.
This number includes both explicit BEGIN WORK commands
that sessions issue and BEGIN WORK commands that
ALLBASE/SQL generates.
COMMIT WORK The number of COMMIT WORK commands being processed.
ROLLBK WORK The number of ROLLBACK WORK commands
being processed. This number includes both the ROLLBACK
WORK commands the session issues and the ROLLBACK WORK
commands ALLBASE/SQL issues against the session to
resolve deadlocks.
DEADLOCKS The number of deadlocks being encountered.
LOCK REQTS The number of lock requests being processed.
LOCK WAITS The number of lock requests postponed because another
session held an incompatible lock.
LOCK WAIT % The percentage of lock requests postponed because
another session held an incompatible lock.
Display Conventions
Characters displayed in the horizontal bars have special meanings, as
explained in the following table:
Legend
----------------------------------------------------------------------------------------------
| | | |
| Symbol | Corresponding Number | Description |
| | | |
----------------------------------------------------------------------------------------------
| | | |
| ! | CUR | Represents activity that has |
| | | occurred during the most recent |
| | | refresh interval. |
| | | |
----------------------------------------------------------------------------------------------
| | | |
| * | AVG | Designates the average amount of |
| | | activity that has occurred since |
| | | SQLMON has been attached to the |
| | | DBEnvironment. |
| | | |
----------------------------------------------------------------------------------------------
| | | |
| $ | AVG and CUR | Indicates that the average value |
| | | is the same as the value of the |
| | | most recent refresh interval. |
| | | |
----------------------------------------------------------------------------------------------
| | | |
| Full bright inverse | MAX | Designates the maximum amount of |
| video | | activity that has occurred since |
| | | SQLMON has been attached to the |
| | | DBEnvironment. |
| | | |
----------------------------------------------------------------------------------------------
Related SET Commands
Use the SET REFRESH command to modify the refresh rate of the screen.
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