LAN Times Guide to SQL

LAN Times Guide to SQL

by James R. Groff, Paul N. Weinberg
     
 

This book describes what SQL is,why it is important,and how to use it. SQL is Structured Query Language developed at IBM as a standard Query and Programming language for all their networked computers. This book is not specific to one brand or dialect of SQL. Rather,it describes the core of the SQL language and the differences among the most popular SQL variations…  See more details below

Overview

This book describes what SQL is,why it is important,and how to use it. SQL is Structured Query Language developed at IBM as a standard Query and Programming language for all their networked computers. This book is not specific to one brand or dialect of SQL. Rather,it describes the core of the SQL language and the differences among the most popular SQL variations such as OS/2,Oracle,Sybase,Ingres,and dBASE IV. The authors use step-by-step explanations of the language,and how and where it is implemented,and also addresses programming SQL.

Product Details

ISBN-13:
9780078820267
Publisher:
Osborne/McGraw-Hill
Publication date:
12/01/1994
Series:
LAN Times Series
Pages:
664
Product dimensions:
7.33(w) x 9.18(h) x 1.31(d)

Related Subjects

Read an Excerpt

Chapter 3: SQL in Perspective

SQL on Personal Computers

Databases have been popular on personal computers since before the introduction of the IBM PC. Ashton-Tate's dBASE product has been installed on over one minion MS-DOS-based PCs, and other products such as R:BASE, PFS:File, and Paradox have also achieved significant success. On the Macintosh, databases such as 4th Dimension combined data management and a graphical user interface. Although these PC databases often presented data in tabular form, they lacked the full power of a relational DBMS and a relational database language such as SQL.

SQL had little impact on personal computers until the late 1980s. By then, powerful PCs supporting tens or hundreds of megabytes of disk storage were common. Users also were linking personal computers into local area networks, and wanted to share databases. In short, PCs began to need the features that SQL and relational databases could provide.

The early SQL-based databases for personal computers were versions of popular minicomputer products that barely fit on personal computers. Professional Oracle, announced in 1984, required two megabytes of memory on an IBM PC, and Oracle for Macintosh, announced in 1988, had similar requirements. A PC version of Ingres, announced in 1987, fit (just barely) within the 640KB limitation of MS-DOS. hiformix-SQL for MS-DOS was announced in 1986, providing a PC version of the popular UNIX database. Also in 1986, Gupta Technologies, a company founded by an ex-Oracle manager, announced SQLBase, a database for PC local area networks. SQLBase was among the first PC products to offer a client/server architecture, a preview of thePC LAN database announcements to come.

The real impact of SQL on personal computers began with the announcement of OS/2 by IBM and Microsoft in April 1987. In addition to the standard OS/2 product, IBM announced a proprietary OS/2 Extended Edition (OS/2 EE) with a built-in SQL database and communications support. With the introduction, IBM again signalled its strong commitment to SQL, saying in effect that SQL was so important that it belonged in the computer's operating system.

OS/2 Extended Edition presented Microsoft with a problem. As the developer and distributor of standard OS/2 to other personal computer manufacturers, Microsoft needed an alternative to the Extended Edition. Microsoft responded by licensing the Sybase DBMS, which had been developed for the VAX, and began porting it to OS/2.

In January 1988, in a surprise move, Microsoft and Ashton-Tate announced that they would jointly sell the resulting OS/2-based product, renamed SQL Server. Microsoft would sell SQL Server with OS/2 to computer manufacturers; Ashton-Tate would sell the product through retail channels to PC users. In September 1989, Lotus Development added its endorsement of SQL Server by investing in Sybase. Later that year, Ashton-Tate relinquished its exclusive retail distribution rights and sold its investment to Lotus. Although SQL Server for OS/2 met with only limited success, SQL Server continues to play a key role in Microsoft's product plans. It is Microsoft's relational database for Windows NT, Microsoft's flagship operating system for client/ server computing, which began shipping in 1993.

SQL on PC Local Area Networks

The introduction of OS/2 Extended Edition and the Ashton-Tate /Microsoft SQL Server focused attention on the potential of SQL in local area networks. Customers began looking seriously at networks of personal computers and the client/server architecture as an alternative to a centralized minicomputer or mainframe for database applications.

Initially, the market for SQL on PC LANs focused on OS/2 as a database server platform. Unlike MS-DOS, OS/2 had no 64OKB memory limit, and its multitasking architecture made it an excellent technical foundation for a database server. By the end of 1989, IBM, Microsoft, Oracle, Gupta and others had introduced OS/2 products. But OS/2's sales fell well below initial expectations, while sales of Microsoft Window began to soar with the introduction of Windows 3.0. Despite attempts to paper over their differences in public, the resulting rivalry between OS/2 and Windows produced a deeper and deeper rift between IBM and Microsoft. In the end, Microsoft acknowledged its commitment to Windows and its lack of support for OS/2, leaving OS/2 with an "IBM proprietary" status. OS/2 continues to be an important platform for some large IBM corporate accounts, but its chance to become the dominant "industrial-strength" PC operating system-and hence the preferred platform for SQL on local area networks-is gone.

While the Windows versus OS/2 battle raged on the desktop, SQL database sales on other PC LAN platforms began to grow significantly UNIX-based computers steadily dropped in price, and a version of UNIX from the Santa Cruz Operation (SCO UNIX) became a favorite platform for Intel-based PCs. In the early 1990s, SCO UNIX added support for multiprocessing, a technique for spreading the workload of a computer over two, three or more microprocessors. With the processing power of four or eight microprocessors working together, UNIX-based versions of Oracle, Informix and Sybase could now deliver minicomputer-level performance on PC servers starting at $20,000. Multiprocessing servers from Compaq, Dell, IBM and other leading PC vendors currently offer the best performance for the price of any computer system available.

Although UNIX became a popular platform for database servers, the vast majority of PC LAN servers were still used for file and printer sharing, and most of those servers used Novell's Netware as a server operating system. Netware lacked the sophistication of UNIX or OS/2, but it had a major advantage-sales volume. The early Netware SQL databases were inferior to those available for UNIX or OS/2, but beginning in 1992 the major database vendors introduced Netware versions. Sales of these products quickly became very strong, and Netware has emerged as a viable PC LAN database platform.

In competition with UNIX, OS/2 and Netware, Microsoft has thrown its weight behind Windows NT as a PC LAN client/server platform. Windows NT has some major technical advantages over the competition; it is a new, modern operating system without the "baggage" of backward compatibility But the lack of installed base, few applications, and the need to build an entire sales and support infrastructure slowed the acceptance of NT. With Microsoft's weight behind it, however, most analysts believed that NT would eventually assume a prominent role in client/server LANs. As a result, all of the leading database vendors have announced NT versions of their products. The first of these products began shipping in 1993.

The market for client/server databases on PC LANs has developed more slowly than the file server and print server markets, but it reached a turning point by 1993. It is now the fastest growing segment of the PC LAN server market. Most analysts expect that growth to accelerate further and to continue into the late 1990s, eventually making PC LAN servers the largest market for SQL-based databases.....

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