SQL Server 2000: A Beginner's Guide (Book/CD-ROM)

Chapter 1: Database Systems and SQL Server

MS SQL Server is a database management system (DBMS) developed and marketed by Microsoft. This system is the most important part of Microsoft Back Office, an enterprise suite of client/server applications. (In addition to SQL Server, Microsoft Back Office includes Windows NT Server, SNA Server, Systems Management Server, Exchange Server, Microsoft Transaction Server, Internet Information Server, and MSMQ Server.)

MS SQL Server runs exclusively under Microsoft operating systems Windows NT/ 2000 and Windows 9x. Microsoft's decision to concentrate on only two of their own operating systems has a lot of benefits and one disadvantage. The most important benefits are as follows:

• MS SQL Server works as a natural extension of Windows NT/2000 (i.e., Windows 9x), because it is so closely integrated with this operating system. As such, the user does not have to learn another user interface to work with this database system.
• MS SQL Server has the same easy setup and maintenance of Windows NT/2000. This unity is accomplished through easy installation of the system, elimination of many complicated tasks concerning database administration, and, generally, using a graphical computing environment for every system administration task. MS SQL Server uses the services of Windows NT/2000 to offer new or extended database capabilities, such as sending and receiving messages and managing login security.

On the other hand, by focusing only upon Microsoft operating systems, SQL Server cannot benefit from the advanced properties of an operating system such as UNIX, which, in some areas like enhanced parallel architectures or enterprisecomputing, still has advantages over Windows NT/2000.

The most important aspects of SQL Server are as follows:

• SQL Server is easy to use.
• SQL Server scales from a mobile laptop to symmetric multiprocessor (SMP) systems.
• SQL Server provides data warehousing features that until now have only been available in Oracle and other more expensive DBMSs.

Almost all relational DBMSs originated under the UNIX operating system. The consequence is that existing user interfaces provided by these systems are rather difficult to use. Microsoft's goal is to make SQL Server the easiest database system for implementing and managing database applications. One way SQL Server helps to further this goal is by providing wizards for almost all administrative tasks.

Scalability means that the same DBMS runs on mobile laptop computers, single-processing systems, and multiprocessing hardware systems. One of the goals of such a DBMS is to scale from the single-processing computer to an SMP if the DBMS becomes CPU-bound because of CPU-intensive database applications. Microsoft bundled the Analysis Services with SQL Server to create a comprehensive approach to the process of data warehousing. The goal of Analysis Services is to make it easier to build data warehousing and data mart solutions using Microsoft's new OLAP technology as well as the existing technology of other data warehousing software companies. Part IV will provide additional detailed information on the data warehousing features of MS SQL Server.

The SQL Server database system was originally developed and implemented by Sybase Inc. Microsoft licensed this DBMS in 1988 for the OS/2 operating system and began the implementation of it for Windows NT/2000 in the early 1990s. At almost the same time, the further development of SQL Server for OS/2 was canceled. In April 1994, Microsoft ended their cooperative agreement with Sybase lnc.

SQL Server was, from the beginning, designed as a client/server DBMS. The client/ server architecture has been developed to manage a large number of different computers (PCs, workstations, and SMP machines), which are connected using a network. The functionality of SQL Server is divided between clients and server(s). A client provides one or more different user interfaces that are used to formulate a user request to a DBMS. The server (i.e., DBMS) processes this request and sends the result back to the client.

NOTE: The client/server architecture does not necessarily include a DBMS. It is also possible to have other exclusively specialized servers, such as a print server and computing server, in such an environment. However, a DBMS is almost always a part of client/server architecture.

A database system is an overall collection of different database software components and databases containing the following parts:

• Database application programs
• Front-end (i.e., client) components
• Database management system(s)
• Databases

A database application program is special-purpose software that is designed and implemented by users or implemented by third-party software companies. In contrast, front-end components are general-purpose database software designed and implemented by a database company or delivered as third-party software. By using database application programs and front-end components, users can manage and query data within the database...