Beginning Microsoft SQL Server 2008 ... - S3 Tech Training

Chapter 2: Tools of the Trade
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log in to the default instance of SQL Server that is on this same machine, regardless of what this
machine is named. Selecting “.” (local) not only automatically identifies which server (and instance)
you want to use, but also how you’re going to get there. You can also use “(local)” as another option
that has the same meaning as ".".
SQL Server allows multiple instances of SQL Server to run at one time. These are
just separate loads into memory of the SQL Server engine running independently
from each other.
Note that the default instance of your server will have the same name as your machine on the network.
There are ways to change the server name after the time of installation, but they are problematic at best,
and deadly to your server at worst. Additional instances of SQL Server will be named the same as the
default (HOBBES or KIERKEGAARD in many of the examples in this book) followed by a dollar sign,
and the instance name, for example, SIDDARTHA$SHRAMANA.
If you select “.” or (local), your system uses the Shared Memory NetLib regardless of which NetLib you
selected for contacting other servers. This is a bad news/good news story. The bad news is that you give
up a little bit of control. (SQL Server will always use Shared Memory to connect; you can’t choose anything
else.) The good news is that you don’t have to remember which server you’re on and you get a high-performance
option for work on the same machine. If you use your local PC’s actual server name, your communications
will still go through the network stack and incur the overhead associated with that, just as if
you were communicating with another system, regardless of the fact that it is on the same machine.
Now what if you can’t remember what the server’s name is? Just click the down arrow to the right of the
server box to get a list of recently connected servers. If you scroll down, you’ll see a Browse for More option.
If you choose this option, SQL Server will poll the network for any servers that are advertising to the network;
essentially, this is a way for a server to let itself be known to other systems on the network. You can
see from Figure 2-7 that you get two tabs: one that displays local servers (all of the instances of SQL Server
on the same system you’re running on) and another that shows other SQL Servers on the network.
You can select one of these servers and click OK.
Figure 2-7