Database Reference
In-Depth Information
Figure 1.2
Hot-add additional memory.
The World Before Database Virtualization
You think to yourself what the world used to be like for you. You would size the
physical server housing the database to accommodate the workload you expected at the
time, and at some point in the future, you would buy as much excess capacity as you
were able to justify to management, knowing full well that this excess capacity in the
server would go unused. However, as a DBA, you would have peace of mind. The
company, on the other hand, would have spent a lot of money without receiving real
value for it in return.
In this scenario, you would have undersized the server, and Cyber Monday would have
come upon you and you would be completely out of luck. You would not have any
options. But you are desperate—there must be some way you can get the server more
memory.
Wait, you realize you have two identical servers in your environment. One housing the
database, and one housing the other applications. You could take both systems down and
then borrow memory from one server to put in the server with the database. While you
are swapping the memory around, the database would be down, but you decide to do it
anyway. You take the systems down. You swap out the memory. You put the additional
memory in the database server. You reboot the system and then start up the database so
that it can see the additional memory and take advantage of it.
