328 Performance Tuning for Content Manager
increase of transaction throughput and a reduction of transaction length
(measured in time units). Thus, locks are not held as long as before.
In this example, we just monitored the Library Server database. Without going
into further details, we note that Performance Expert enables you to open
windows that provide graphical views to simultaneously monitor the Library
Server database and the Resource Manager database.
Recommendations for using PE to monitor CM databases
DB2 Performance Expert Server is a sophisticated monitoring and analysis
application that is built on DB2. This means that it adds a certain load to the
When using it, we recommend avoiding resource contention and keeping
monitoring completely separated from your Content Manager server workload.
You should install the Performance Expert server on a different machine than the
Library Server and the Resource Manager.
11.4.3 DB2 analysis tools
In 11.4.2, “DB2 monitoring tools” on page 309, we give an overview of the tools
that you can use to monitor a database environment in order to identify a problem
if there is any. You might not be able to retrieve sufficient information from the
monitoring tool to solve some problems. In some cases, you might need to
perform further analysis at the operating system level (for example, if it comes to
the impact of low buffer pool hit ratio on disk I/O) and in other cases, you may
need to use DB2 analysis tools. This is typically the case when you figure out that
execution of a specific SQL statement is very slow and consumes unreasonably
high CPU or I/O resources in your database system. In the DB2 Explain section,
we describe recommended steps toward identifying the cause of the problem
and helping you find a way to solve it.
We discuss two DB2 analysis tools here:
DB2 Design Advisor
As described in 2.1.3, “Performance-related concepts” on page 39, DB2 involves
the SQL query optimizer to evaluate and compare the cost of access plans to
finally choose the access plan that appears to be most efficient. Nevertheless,
even when using this best access plan, the query execution might turn out to be
very expensive. This is typically observed by the user as long response time or
by the database administrator as a high load on disks and network. Using the
monitoring tools described earlier in this chapter, you will be able to identify this