Databases relate to the Web

At first glance, enterprise database systems might seem to be super-sized versions of desktop database applications such as Microsoft Access. But any confusion between the two wouldn't last long.Enterprise database systems are highly scalable, serving anywhere from 10 or 20 users in a small workgroup to thousands of networked users.Desktop databases typically cost several hundred dollars each, while enterprise database servers can cost thousands of dollars per server, depending on the number of licenses required or the options added to the core program.And unlike desktop products, enterprise databases are notoriously difficult to set up and manage. Even midsize enterprises generally require one or more database administrators to keep the programs up and running.The job of an enterprise database also is considerably more daunting. Considering government agencies' mission to collect, store, transform and transmit huge amounts of information, databases are absolutely essential.Among the several classifications of databases, the relational database management system (RDBMS) is far and away the most popular. Gaining momentum are two types more suited to the Web'post-relational object databases and Extensible Markup Language databases.Unlike two-dimensional flat-file databases, in which all data is stored in a single file, relational databases store data in multiple flat files connected by shared data fields called keys. Users can query these files by using a language, usually Structured Query Language, understood by all related databases. With the help of SQL, relational databases can provide an array of information to users who may or may not understand how a database works.The RDBMS market is robust and growing steadily. Enterprises worldwide spent $8.8 billion on RDBMS in 2001 and will spend nearly $20 billion by 2006.Last year, four database vendors accounted for more than 80 percent of the total amount spent on RDBMS worldwide, according to Gartner Inc., a market research company in Stamford, Conn. Oracle Corp., maker of Oracle9i, accounted for 33.8 percent of the total. IBM Corp., which makes DB2 Universal Database 7.2, wasn't far behind, with 30.1 percent. Microsoft Corp.'s SQL Server 2000 Service Pack 2 came in with 14.9 percent. Sybase Inc.'s Adaptive Server Enterprise 12.5 came in fourth with a 3.9 percent market share but is still considered a market leader.All four companies have zeroed in on keys to success in the RDBMS world:Internet use. Software vendors have come to see that enterprises worldwide, including government organizations, will succeed or fail according to their ability to share information online.SQL. Virtually all relational databases support this standard language for querying database files. In fact, many users now use the terms 'SQL database' and 'relational database' interchangeably.Transaction processing. The ability to handle multiple transactions simultaneously is the bread and butter of RDBMS. Online transaction processing (OLTP) and transaction logs are built into all the major relational databases.Manageability. Complex RDBMS technology isn't known for being user-friendly. The best RDBMS software contains advanced wizards that guide users through complex tasks, such as database and table creation or Web publishing. Graphical tools are also part of the RDBMS arsenal.Data security. A good system performs safety checks whenever data is changed. It may write data to a transaction log as well as to the database itself. If a mistake occurs as a result of a series of database commands, the commands can be rolled back in order until the error is corrected. Software and hardware fault tolerance is also built into most programs.Advanced data management. A growing trend is toward built-in support for advanced data management features such as data warehousing, data analysis and data mining. Microsoft built limited support for data warehousing and online analytical processing (OLAP) into earlier versions of SQL Server and has enhanced them in its latest version. Oracle and IBM have followed suit.Open source. To meet demands for open systems software, Oracle, IBM and Sybase have added support to their core services for open standards such as Java and XML.Can open-source programming save time and money? Two nonproprietary open-source database programs, MySQL 4.0 and PostgreSQL 7.3, are gaining credibility. Supporters say both support a wide range of operating systems and can reduce licensing and handling costs. But critics say that they can't scale up to handle more demanding enterprise workloads.As good as it is, RDBMS technology has limits. Relational databases understand only limited and simple types of data, such as integers, dates and character strings. More complex data types, such as those used in e-commerce and Web applications, require new database architectures.According to the Aberdeen Group Inc., a high-tech market research company in Boston, object-oriented databases are designed for the complex logic and rapid deployment of Web applications, as well as having built-in tools such as XML and Web services.'The new databases are 'low profile''they can be embedded in the Web application, allowing low administrative costs and higher performance,' a recent Aberdeen report said.Cache 5 from InterSystems Corp., for example, is a post-relational object database that combines object, SQL and multidimensional technologies.Relational database systems are well-suited to manage data that fits into rows and columns, but they fail when called on to manage rich data such as audio, video, nested data structures or complex documents. All are characteristic of Web content.The XML standard, developed by the World Wide Web Consortium and endorsed by industry heavyweights, is an open standard for storing, publishing and exchanging any kind of information. It lets business information keep its independence from proprietary data formats and remain readable forever.Some industry insiders are calling XML the most significant change in computing since the invention of relational databases and SQL.As a result, many RDBMS vendors are jumping onto the XML bandwagon by building special XML extensions into their core products. This is a step in the right direction, but it will result in products that can never be as cost-effective and robust as native XML databases, according to Software AG and other XML developers.Expect more XML databases to come to market soon, as enterprises catch on to the value of XML for meeting their e-business requirements.