Datasheet

MSDTC (Distributed Transaction Coordinator)
The MSDTC service is used to manage transactions that span more than one instance of SQL Server or an
instance of SQL Server and another transaction-based system. It utilizes a protocol known as Two-
Phased Commit (2PC) to ensure that all transactions that span systems are committed on all participat-
ing systems.
SQL Server 2005 Database Objects
SQL Server 2005 database objects are defined and exist within a defined scope and hierarchy. This hierar-
chy enables more control over security permissions and organization of objects by similar function. SQL
Server 2005 objects are defined at the Server, Database, and Schema levels.
Server
The server scope encompasses all the objects that exist on the instance of SQL Server, regardless of their
respective database or namespace. The database object resides within the server scope.
One of the more confusing terms when working with SQL Server 2005 is the term server. When you hear
the term “server,” you often think of that piece of hardware taking up space on a server rack in the server
room. Where the confusion arises is that you can install multiple instances of SQL Server on a single
server (huh?).
What would probably be clearer is to say that the capability exists to install multiple instances of the
SQL Server 2005 Data Platform application on a single computer running a Windows operating system.
Though this might be more descriptive, it doesn’t make for very interesting marketing material.
What is left is the fact that, when it comes to SQL Server 2005 and you read “server,” it is important to
check the context to make sure that it means an instance of SQL Server 2005 or the physical computer
that SQL Server is installed on.
When it comes to the server scope and SQL Server 2005 database objects, the term “server” actually refers
to the SQL Server 2005 instance name. In the majority of the examples in this book, the instance name is
AUGHTFIVE, which is also the name of the server used in the writing of this book. So, the instance name
AUGHTFIVE is the default instance installed on the Windows Server 2003 named AUGHTFIVE.
Database
The database scope defines all the objects within a defined database catalog. Schemas exist in the
database scope.
The ANSI synonym for “database” is “catalog.” When connecting to an instance of SQL Server 2005, it is
generally desired to specify an Initial Catalog, or Initial Database. An instance of SQL Server 2005 can
contain many databases. A typical database application is constrained within one database that contains
all the data objects required to provide the functionality the application requires. This is not always the
case, but it is the most common.
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