SQL Server 2000 Overview and Migration Strategies

Introduction

Microsoft Structured Query Language (SQL) Server 2000 is the latest generation of the popular SQL Server product line and the second release since its core reengineering that produced SQL Server 7.0, released in 1999. This latest release of SQL Server adds native Extensible Markup Language (XML) support, enhanced online analytical processing (OLAP), data-mining capabilities, platform support for Windows 2000, integration with Windows 2000 Active Directory, and numerous performance, usability, and programming enhancements. SQL Server 2000 is available in six different editions to meet all levels of application development and delivery:

■ SQL Server 2000 Enterprise Edition

■ SQL Server 2000 Standard Edition

■ SQL Server 2000 Personal Edition

■ SQL Server 2000 Developer Edition

■ SQL Server Desktop Engine (MSDE)

■ SQL Server 2000 for Windows CE Edition

To meet scalability and availability goals, SQL Server 2000 is the first release designed and built to take advantage of Windows 2000 with support for up to 32 processors and 64GB of memory running on Windows 2000 Datacenter Server. Windows 2000 Active Directory integration adds enhanced server and security management features to SQL Server. The latest version of OLAP support, now called Analysis Services, provides numerous wizards for ease of use and the setup of OLAP and new data-mining solutions. One of the more publicized additions to SQL Server is its native support for XML. SQL Server 2000 offers support for storing, using, and updating XML documents—an important requirement because XML becomes the language of choice for many business systems and a fundamental architecture component of Microsoft .NET.

SQL Server 2000 is the first released member of the .NET Enterprise Server family and offers numerous advantages to organizations considering migration to this new platform. Enhancements in reliability, scalability, performance, and administration, along with strong compatibility with previous versions, make this release a strong candidate for early adoption into SQL Server 7.0 environments and an immediate migration from organizations running on SQL Server 6.5. Native XML support in SQL Server 2000 will help many organizations begin implementing this technology, which is quickly becoming a standard to both external and internal systems, including e-commerce, Web application services, and line-of-business applications.

This chapter discusses the changes in SQL Server 2000 as well as assists you in understanding the direction of Microsoft Windows Distributed interNet Applications (DNA) Architecture Model toward .NET and the role of XML. You will review the available editions of SQL Server 2000 and their features and requirements so that you can choose the appropriate edition for your organization. The second half of this chapter discusses whether you should migrate to SQL Server 2000 as well as lays the groundwork for planning your migration.

Overview of SQL Server 2000: A .NET Enterprise Server

In September 2000, Microsoft officially announced its .NET Enterprise Server line and its commitment to .NET as Microsoft’s application architecture model. The fundamental goal behind this new release of the company’s popular server product line, now labeled .NET Enterprise Servers, is to provide simplified management, scalability, and availability throughout the enterprise, meeting the application goals of every organization and offering extensive support for .NET applications. SQL Server 2000 is the first .NET Enterprise Server available for public implementation and offers the data storage and management component of .NET services as well as a peek into the Microsoft’s vision of .NET application capabilities.

Before we can see where the future will take us, it’s always good to understand exactly where things came from. Microsoft SQL Server was first released as version 6.0 soon after Microsoft purchased and modified the code base to SQL Server from Sybase Corporation in 1995. Through version 6.5, released in 1996, SQL Server was accepted mainly as a departmental-scale database management system (DBMS) and lacked much of the scalability and reliability of enterprise-class solutions offered by companies such as Oracle and Informix.

Administration of the SQL Server 6.0 and 6.5 products required knowledgeable SQL Server database administrators committed to monitoring server availability, activity, and performance. For SQL Server to have the broad market reach that Microsoft aims for in most of its products and to make it a fundamental component in its then-new Windows Distributed interNet Applications (DNA) Architecture Model, Microsoft needed to address the broad range of concerns and downfalls that plagued SQL Server’s acceptance in both large and small organizations. In 1999, after several years of development and complete reengineering, Microsoft released SQL Server 7.0, which offered numerous enhancements in reliability, functionality, administration, security, performance, and scalability and allowed SQL Server to become the most popular relational database management system (RDBMS) in the market, with over 60 percent of all Web databases running on SQL Server by the end of 1999 and 70 percent of the total databases running on the Windows platform.

Soon after Microsoft launched SQL Server 7.0, several enhancements to the product, such as the XML Technology Preview, the OLAP Manager Add-In, and DTS Task Kit as well as two (now common) service pack updates, were released as downloadable additions. With the aggressive schedules and demanding markets that you and I represent, service packs are bound to continue, but all the previous additions and fixes have been refined and included in SQL Server 2000, along with countless enhancements in performance, availability, scalability, programmability, and management. SQL Server 2000 is light years ahead of the days of version 6.0 and is a required upgrade for nearly every SQL Server-based application.

The Future of Windows DNA: Microsoft.NET

In 1997, Microsoft announced the Windows Distributed interNet Applications (DNA) Architecture Model, which laid the foundations for building scalable, Web-based solutions based on Microsoft’s line of servers, technologies, and development tools. Emerging from the popular, two-tier (or client/server) application architecture, DNA presents a distributed n-tier architecture model incorporating Web technologies such as Microsoft’s Internet Information Services (IIS), including Active Server Pages (ASP), standard Web browser software such as Internet Explorer or Netscape Navigator, protocols including HyperText Transfer Protocol (HTTP), and enabling technologies such as Component Object Model (COM) and Data Access (ActiveX Data Objects, OLE DB). Via standard Web browser software, users are allowed access to DNA applications with little if any need for configuration of the client. Application services are centrally managed and delivered from the enterprise for enhanced reliability, scalability, and performance. This popular application architecture model accounted for roughly 40 percent of all secure, transacted Web-based applications built by the end of 1999.

The DNA Architecture Model is logically divided into three layers:
Presentation Services, Business Services, and Data Services. Each layer plays a specific role in the application, as depicted in Figure 1.1.

The Presentation Services layer encompasses the Web browser and client-side services such as HyperText Markup Language (HTML) to interpret and display Web pages, VBScript, and JavaScript for user input validation, Dynamic HTML (DHTML) for interface enhancements, and Java Applets or ActiveX Components for enhanced client-side functionality. The Business Services layer is responsible for much of the “work” in the application and handles tasks such as processing user input, applying business rules and application logic, validating data in and out of the Data Services layer, and delivering the application to the Presentation Services layer. The third layer of the DNA model is Data Services, which is responsible for storing and managing all types of information, including databases, document storage, e-mail, and directory services data.

Now that you have a basic idea of the principles behind the DNA Model, we can discuss the Windows DNA Platform. The DNA Platform is the collection of software products, technologies, and tools that are used to physically build, host, and manage DNA applications. Having a conceptual model makes the theory of scalable, reliable, Web-based applications understandable, but to make it a reality, you need to be able to actually construct the layers to form your application. The Windows DNA...