This screen provides information about locking performance.
The following information is examined:
o Lock stalls, timeouts, and deadlocks
o Excessive timeouts or deadlocks
Information in the Locking Analysis screen is displayed only if
it exceeds established threshold values or normal expectations.
Note that the items identified in this screen are not necessarily
indications of performance problems. The items may be an
indication of a performance problem, but in most cases, further
research is necessary.
The Locking Analysis screen has a configuration submenu that
allows you to set thresholds for the following:
o Lock stall threshold
The default threshold is 2 seconds. You can override the
default value with the RDM$BIND_STATS_MAX_LOCK_STALL logical
name.
Note that the Online Analysis facility uses the actual database
parameters and attributes specified using interactive SQL. The
Online Analysis facility does not use the Dashboard facility
because the Database Dashboard attributes are temporary settings.
Therefore, online changes made using the Dashboard facility are
not reflected in the analysis output. Yet, using the Dashboard
facility is the recommended method for testing potential database
attribute settings. You must use interactive SQL in order to make
the attribute settings persistent.
Also note that the Online Analysis facility is invoked at the
designated screen refresh interval. As the Online Analysis
facility is fairly CPU intensive, and the analysis results seldom
vary greatly over a miniscule period of time, it is recommended
that the screen refresh interval be set to 3 seconds or more.
The Locking Analysis screen is not recorded in the binary output
file produced using the Output qualifier. Consequently, this
screen is not available when you replay a binary file using the
Input qualifier.