Chapter 12 will focus on Oracle Parallel
Query and show different methods that can be used to invoke
parallelism in cases where full table scans are being performed
against large tables. We begin by showing how to find large-table
full table scans and then discuss the different methods that can be
used for parallelizing these kinds of queries. We'll also show how
to set the degree of parallelism in order to maximize the throughput
and execution time of the individual query, based on the number of
CPUs and the number of disks for the table's file.
We will also discuss parallel Data Manipulation
Language (DML) and how operations such as parallel index rebuilds can
improve the speed of database maintenance activities using SQL
updates, inserts and deletes. Chapter 12 also examines how submitting
concurrent requests to Oracle can parallelize many large Oracle tasks.
Tuning Real Application Clusters (RAC)
Chapter 13 will discuss Oracle Parallel Server
(Oracle7 through Oracle8i) and Real Application Clusters environment
(for Oracle9i). We will also describe the characteristics of
application systems that will benefit from using an Oracle Parallel
Server (OPS) or Real Application Clusters (RAC) environment. We will
discuss the configurations necessary for clustered hardware and also
take a look at application partitioning techniques that can be used to
maximize throughput in an OPS or RAC environment. This chapter will
also take a look at determining the optimal number of instances for
OPS and RAC, and look at the Integrated Distributed Lock Manager (IDLM)
for OPS. We will take a close look at the IDLM parameters, and show
how STATSPACK can be extended in order to collect information on the
behavior of the IDLM in a production environment. We'll also take a
close look at pinging between instances, and understand how pinging
can be minimized by partitioning application structures.
Now that we have covered the overall approach
to tuning, we need to look at how STATSPACK is used to facilitate the
tuning effort.