Central, Peformance Diagnostic Module -Tool for Hybrid DBA
Quest Software has made history with Instance Monitor, then Spotlight
and now Quest Central. With each new installation, the application package is larger
and larger. With the last software incarnation, Quest Central provided a unified
console for a set of tools where instance monitoring is provided through an integrated
module, Performance Diagnostic Module.
This module is a great tool for DB2 activity monitoring and
You can watch real time database activity, compare
graphical charts for various resource utilizations, and get very good
interactive help, rich with advice and hints. Visual representation identifies
database areas with red, yellow and green colors. Critical events are marked
red, warning events yellow and green represents regular, normal activity.
DBAs used to keep the interactive graphical console open on the
desktop all of the time. This allowed a problem to be spotted before the
customer made an emergency call or we started the problem detection with event
monitors. The hybrid DBA, armed with database
activity charts and with good tuning experience can solve extremely complicated
situations in a very short time.
has the capability to collect all information from the OS such as CPU,
memory, disk utilization and virtual memory as a snapshot of overall system
of the resources from OS side will be identified; collected system information
can be compared with the database activity charts.. Armed with this
information, the DBA can ascertain if the system is well dimensioned for the
actual type of load.
If all of
the performance diagnostic module charts show lots of database reads, full
table scans, and huge sort and lock activity, then the DBA knows that something
was executed, some heavy SQL. The performance diagnostic module can call
another integrated module (SQL tuning module), which can uncover problematic
SQL from the database global memory. You can sort all of the cached SQL
commands by the user, time, disk reads, logical reads and many other ways.
and explaining problematic SQL query is very easy. Information collected by the
tool is enough for the DBA to open a call to the developers for correction of
the code or DBA can along with SQL Tuning module, make error corrections and
optimizations of the SQL code. The SQL Tuning module is very easy, intuitive
and has many advanced features, which can help in code optimization.
Cons: The performance diagnostic
module does not have any historical features. You can collect almost 24 hours
on your charts, however, after 24 hours, additional data collection is continued
by overwriting the previous data. During the tool installation procedure, we
need to know the database user with DBA rights, and we must have enough space
in the database for installation numerous proprietary objects. On every
upgrade, the repository must be rebuilt from scratch. You should consider
allocating separate tablespace for that.