Databases Reference
In-Depth Information
CHAPTER ONE
Used to Be
Odds are very good that one or more of your com-
pany's database applications is suffering from per-
formance issues. This should hardly come as a surprise to
those who deal with application design, development, or
deployment. What may be surprising is that the root
cause of many of these issues is the database middle-
ware, the software that connects applications to data-
bases.
When we say performance issues, we mean your appli-
cation is suffering from unacceptable response time,
throughput, or scalability.
Response time
is the elapsed time
between a data request and when the data is returned. From
users' points of view, it is the time between when they ask for
some data and when they receive it.
Throughput
is the
amount of data that is transferred from sender to receiver
over a period of time.
Scalability
is the ability of an applica-
tion to maintain acceptable response time and throughput
when the number of simultaneous users increases.
Before we get into why database middleware is so
important to the optimal performance of your database
applications, let's look at how the performance landscape
has changed over the past decade.
1
