What are databases?


We use databases so much we don't even think about the fact that we are using databases

Database blue stack icon Does the word database sound technical and forbidding? It shouldn't because we use databases comfortably everyday. In fact, we use them so much we don't even think about the fact that we are using databases.

During the course of a day we might use a telephone directory, a dictionary, an encyclopedia, an airline flight guide, a bibliography, Wikipedia, or a Yahoo or Google index. In fact, we use databases to store all kinds of knowledge that we retrieve on a regular basis.

What is it? A database is an organized list of facts and information. Databases usually contain text and numbers, and frequently they hold still images, sounds and video or film clips.

What's the difference between a simple list and a database? A database permits its user to extract a specific group of disparate facts from within a collection of facts.

The paper filing system in an office is a kind of database. However, today we're more interested in databases constructed on computers where database management programs help people design and build collections of information.

Lingo. We use the words database and databank interchangeably. We also use the words data, facts and information here as meaning more or less the same thing.

For instance. Here are some examples of ways we use databases: Citations and abstracts. Many databases offer citations and abstracts of journal articles and books. By searching for keywords that might appear in an article or book, a user can retrieve the citation, and often an abstract, of the journal article or book.

Full text. A full-text database incorporates large files of text such as all of the paragraphs from a journal article or all of the chapters of a book. By searching for keywords that might appear in a text, a user can call forth the citation and abstract of a journal article or book. Today, many such databases do not offer the full text for free. Those with full text usually offer the search for citation and abstract for free, but charge for delivery of the full text of an article.

Updating. A typical database is designed around a central set of facts. All databases permit their operators to add new information or to update old facts whenever needed.

Sorting. In an electronic database stored in a computer, the order of information can be rearranged or sorted quickly. To help people retrieve and print facts, computer databases sort lists into reports.

Boolean logic. An electronic database can be searched rapidly for specific items of information. Often, the search commands incorporate Boolean algebra logic so users can use AND, OR or NOT to eliminate unwanted entries.

Expert system. One kind of database, known as an expert system, presents information on a specialized field. For example, a medical information database might gather expertise from physician specialists, as well as specific facts about drugs. The database might then package and deliver the information as a substitute for direct contact with a physician.

Electronic storage. Most academic databases are stored electronically, either on computers serving the Internet or on CD-ROM or DVD discs.

As personal computers have become powerful in their document storage and retrieval capabilities, sounds, graphics, animations, still photos and video and film clips have been added to Internet databases and CD-ROMs and DVDs. The length of time that data might be readable on a CD-ROM or DVD depends on manufacturing quality and the availability of players, and probably ranges from 2-15 years. However, manufacturers have claimed 30-100 years. At any rate, a DVD is reliable for backup only if it is handled and stored carefully.

Computer networks. A computer network is formed when many computers are interconnected for the sharing of resources. You might like to think of a network as an information highway over which data is transported.

Recently, networks have changed our idea of what computing is, away from mere number-crunching toward communicating. During the last two decades, networks have spawned a new online industry – a collection of organizations providing information services to remote customers via transmission media spanning states, countries and the entire globe. Commercial databases. Many databases are commercial electronic information services that people reach through the Internet. The information packager or reseller is referred to by such names as online database, online service, interactive service, information provider, service provider or content supplier. These online services sell data to their clients and deliver the information through the Internet. The computer storing the seller's information is referred to as a host. While anyone can download, or electronically copy, information from the Internet, businesses with data for sale see protection of their copyright material as a necessity. To protect their intellectual property, companies sometimes go so far as to encrypt the data they sell via the Internet. To make that information useful, they provide decoding keys to buyers of the data. Of course, that scheme alone doesn't prevent buyers from then repackaging and reselling the data.

Commercial online service operators offer their customers access via the Web. To obtain access from home or office, a researcher navigates the Web to the database's home page. Typically, an authorization number and password are required to enter a publisher's commercial database.

Academic research libraries subscribe to various electronic databases of use to scholars. Researchers either go to a Web site using a library password or else visit a physical library's CD-ROM database room. The Internet is not a library. The Internet connects us with a wealth of information on countless topics contributed by people throughout the world. While no one knows for sure how many individual information files reside on the Internet, it could be trillions. The number is growing at a rapid pace.

However, the Internet is NOT a library. Not all available materials are identified. Not all can be retrieved from a single catalog. Many are not authoritative or authentic or scholarly or useful in academic research.

In fact, the Internet is a medium of mass communication – a forum for self-publishing. Anyone with a bit of technical skill and the finances to access a host computer can publish on the Internet.

While some World Wide Web sites demonstrate an expert's knowledge, others are amateur efforts. As with any information resource, it is important to evaluate what you find on the Internet.

Some sites may be updated daily by their owners; others may be way out of date. In addition, the addresses of Web sites can and do change. Information located on the Internet today can disappear tomorrow at the whim of its publisher. Remember that when you locate Web sites of interest to your research.

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What is a database search?

An online database search is simply bibliographic research which is performed by an individual scholar or librarian using a computer and the Internet. By connecting with a database research service, millions of records from thousands of publications in hundreds of databases can be searched for material on a topic. Search results. Citations and abstracts found for relevant items, such as journal articles or books, can be read, saved, printed or e-mailed. Those journals or books then also can be requested from local public and college libraries through the Inter-Library Loan (ILL) service.
How to cite sources »

Who pays for full text? For a fee, full-text database services will mail, fax or open an article for online reading after the user pays for the service. University libraries often provide access to databases for searching and reading of full-text articles at no charge to students and faculty. A different no-expense option for students would be obtaining printed publications via Inter-Library Loan (ILL).

Some important databases do not require passwords. For instance, an extraordinarily extensive database open to everyone is the National Library of Medicine's MEDLINE. Another is ERIC, sponsored by the Institute of Education Sciences of the U.S. Department of Education. Other examples include Google Books and Encyclopedia Astronautica.
Wikipedia list of online databases

An online reference desk offers online access to library catalogs around the world, dictionaries, thesaurus, quotations, encyclopedias, almanacs, glossaries, bibliographies, catalogs, book texts, museums, government sources, thousands of universities' sites, calendars, sourcebooks, directories, mass media, people searches, and all of the Web-wide search engines. There also are resources for online privacy and online education. Such reference desks are open to all.
Wikipedia list of online reference desks

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Further readings about databases and research methods
This list is brief and not exhaustive. There are many other excellent resources.

Resources for Courses »

© 2011 Dr. Anthony Curtis, Mass Communication Dept., University of North Carolina at Pembroke    e-mail    home page