QuickStudy: Data Collections

Computerworld - The explosion of e-business - and the massive amount of data it created - has made data management and organization more important than ever. We often hear the terms database, data warehouse and data mart, but the differences among them aren't always clear. Some experts say that the difference between, say, a data mart and a data warehouse is more conceptual than real. Nonetheless, here are some general rules of thumb to sort out these terms.

In the Beginning . . .

A datum is a raw piece of information that's capable of being moved and stored. In the broadest sense, a database is a collection or aggregation of such data, along with information on how pieces of data relate to one another.

A database is typically organized into records - one record per item, such as an order - that are themselves divided into several fields, with each field containing information about a specific aspect or attribute of the item. For an order, these could include customer data, part numbers, prices and discounts.

In theory, a database doesn't even require a computer, but it certainly makes its use a lot more scalable and efficient, says Mike Schiff, an analyst at Current Analysis Inc. in Sterling, Va. A pocket address book is certainly a database, but searching contact entries by city or industry requires flipping through each page.

Database management systems, such as those from Microsoft Corp., Oracle Corp. or IBM, act as the underlying vault and retrieval technology.

In addition to storing data, a database management system handles security and access control, says Schiff. Business intelligence tools then access this data for analysis. However, databases rarely exist just to run analytical operations; in general, they're vital to running a business.

Database management systems can be organized in different ways. A relational database stores information in tables and then joins or combines those tables across common fields. A hierarchical database stores data in a tree structure; an order record might have every line item underneath it. An object-oriented database encapsulates both data and business logic.