Building a home network
With a minor investment of
money and effort, you can set up your very own Data Guard environment in the
comfort of your own home. The minimum essential equipment you need consists of
two computers using the same operating system version, a router, and some
cable. If you have a second computer lying around, put it to use. It does not
have to be tremendously powerful; in fact, all that is necessary is that it
meets the minimum requirements to install Oracle. If you do not have a second
computer, find a friend who wants to learn and practice Data Guard and is
willing to relocate his computer to your house or office temporarily. Better
yet, see if you can borrow one from work. Getting access to a second computer
is the hardest part of getting some hands-on experience. If you cannot obtain a
second computer, you can configure a standby on your primary database's server,
but there are some extra configuration steps required.
To network the two
computers, you will need a router. Again, this has to be only "good enough."
For around 25 dollars, you can obtain a 4-port broadband router with
4x10/100Mbps switched LAN ports and a 1x10/100Mbps WAN port for a cable modem
connection. If you want to go high tech, get a wireless router and install a
wireless Ethernet adapter. I have a D-Link wireless router at home and I
installed a wireless card on a second computer. Total cost was around $100, and
it took around 30 minutes to put it all together, including the time to open
the CPU and install the card.
On your main computer (a PC
in this case), you access the router via http://192.168.0.1
and perform a few tasks for setup. One item you may want to set is WEP, Wired
Equivalent Privacy. WEP is an 802.11 standard that protects wireless
communication from eavesdropping. Overall, it is quite simple to create a home
Once the router and network
card are installed, Windows may start the networking wizard. One way to confirm
networking is working is to open your favorite Web browser and navigate to an
external page. If you can surf the Web from both computers, that is a good sign
the next test will succeed. This next step needs to be performed anyway,
regardless if your network has an Internet connection.
On each computer, share out
a folder, and then from each computer, use Explorer to open the remote shared
folder. You can also go to My Network Places and discover the other computer on
your network. From "Entire Network," you should be able to drill down to the
computers in your network.
Finally, since this is all
about Oracle in the first place, install the same version of Oracle on each computer
and either create the seed database or make a small one of your own. For the
examples in this series, I will be using Oracle 18.104.22.168 (no patches), which is
freely available at Oracle Technology Network. From each computer's
perspective, you should be able to ping and tnsping the remote computer. Once
all of these tasks and tests are complete, you are ready to configure the
primary and standby database for Data Guard.
In Part Two, we will create
a physical standby database and experiment with applying redo logs against the
standby, fail the primary, and switch over to the standby. In Part Three, we
will create a logical standby and perform a failover. At the end of this
series, you should feel confident in your ability to configure and use each
type of standby database and be able to discuss (or at least know where to find
the information) the differences between the two types of standbys and know
some of the general operational requirements.
See All Articles by Columnist Steve Callan