2012-04-23Performance and Scalability

This chapter is about performance measurements and scalability of databases.

In this context, I am using the following definition for scalability:

You see that there are actually two definitions. The first one is about the effects of growing load on a system. The second one is about growing the system to handle more load.

The second definition enjoys great popularity. Whenever somebody talks about scalability, it is almost always about using more hardware. Scale-Up and Scale-Out are the respective keywords, which were complemented by new buzzwords like Web-Scale recently.

Scalability is, in general, about the performance trend caused environmental changes. Hardware is just one environmental variable that may change. This chapter covers other variables like data volume and system load as well.