Object-oriented database management systems (also known as OODBMSs) are better suited than relational databases (such as SQL Server) for many of today's new information types. Relational databases excel at storing and retrieving large numbers of relatively small pieces of structured data (such as customer names, addresses, dates, and numbers) and managing relatively few (typically fewer than a dozen) relationships to other tables of data.

Object-oriented databases characterize complex relationships among data stored as objects. The stored object contains information about its relationship to other objects: It knows its place in the data hierarchy. Object-
oriented databases are equally adept at handling large, unstructured pieces of data (Binary Large Objects­BLOBs) such as bitmaps, audio clips, and multimedia clips. And, with object-oriented databases (unlike with some relational databases that also support BLOBs), you can store the application code to manipulate the object directly in the database, rather than in a separate application. So you can store both a video clip and the software you need to play the clip in the database. The application doesn't need to have the logic necessary to display the object's data; the object contains the necessary code.

Object-oriented databases can also reference and interact with data in files outside the object database, so an OODBMS lets you store meta-data (information about information) and create an interactive data catalog. These features increase flexibility at a time when new data types and formats are being developed almost daily.

CompuServe and POET
CompuServe needed an object-oriented database to handle the complexities of its forums. The solution was POET Software's POET (Persistent Objects and Extended database Technology) database. POET lets CompuServe improve manageability (the creation, storage, and retrieval of message threads) in its user forums. The most apparent attribute of these messages is that they contain mostly free-form text and relate (as replies) to other messages in the message threads.

CompuServe chose POET Software because it has a very clean object model, it is committed to the Open Database Management Group standard, it provides standard interfaces, and it is easy to work with. POET was eager to work with CompuServe's inhouse developers and satisfy their requirements.

POET's Technical Features
POET version 4.0 offers many advanced features, including support for ODMG-93 (including Object Query Language, a SQL-like language for object databases), Open Database Connectivity (ODBC), Object Linking and Embedding (OLE), symmetrical multiprocessing (SMP), and more.

POET's database is portable because it uses a binary-independent format; the engine automatically converts between CPU formats on different manufacturers' systems. This automatic conversion lets POET run on a variety of operating systems, such as Windows 3.x, Windows 95, NT, Novell, OS/2, Macintosh, and UNIX (Solaris, AIX, HP-UX, SGI IRIX, SunOS, and SCO).

POET runs as language extensions to most popular C++ compilers from Borland, Microsoft, and the native compilers of most operating systems. You can construct user interfaces to POET databases with Visual Basic, Delphi, CASE tools, or other front-end builders. To download a working demonstration of POET's C++ SDK or a beta version of POET's Java SDK, visit the POET Web site.

POET
POET Software * 415-286-4640
Web: www.poet.com
Price: Personal edition (one user) $998; Professional: $1,998