What is a Database?

Posted By BrokenClaw on December 3, 2007

A database is a computer application used primarily by businesses to keep track of all types of data. In fact, any computerized business uses a database of one kind or another.

What makes a database useful is the fact that each piece of data, called a record, is entered into the system individually, but remains linked to its associated records. By the same token, each record can be pulled out individually along with its associated records. The data itself can be text, or a number, or any kind of digital media.

A simple example of a database is a collection of names and addresses. To put the information in the database, each piece of data is typed into it’s own box, called a field. There would be a field for the first name, a field for the surname, a field for the house number, for the street name, the city, state, and zipcode. The data is entered individually, but all of these fields are linked together in the database.

The process just described is familiar to anyone who has ever made an online purchase, because that’s exactly what you’re doing when you fill out the order form. You are entering your personal data into their database. The same process happens whenever you fill out a paper form, except that someone else has to transcribe your written information into their computer database.

Now what makes a database useful is that the data can be searched and pulled out by a process known as a query. For example, you could search the database for all of the people with a particular surname, or all of the people who live in a particular state. A database works by creating indexes of all the records so that it can quickly find the answer to a query. In other words, it doesn’t have to search through every single record looking for a particular surname because it already has an index of the surnames, so it’s like finding a name in a phonebook because you know it’s alphabetical.

Queries can also be combined. In our example, you could search for everyone with a particular surname who lives in a particular city. The database would go to the surname index, find what it needs, then follow the link on those names to the city index and find the ones that match.

In the movie, The Fugitive, Harrison Ford’s character demonstrates the power of the database when he sneaks into the Prosthetics Department and uses the computer to look for the infamous “one-armed man”. You can see him entering sequential queries into the system, by date, by limb, by prosthesis, and by type, until the database has only a handful of patients who match all of the queries. TV and movie detectives show a database in action whenever they use the computer to search for a suspect using particular characteristics.

A database program is often part of a group of software known collectively as an office suite or productivity suite, which may include a word processor, spreadsheet, and presentation software. Open Office is a suite of open source applications which is a free alternative to Microsoft Office.

A database is still primarily a business application, and most home computer users will never have a need to create one. But if you use a computer at all in your job, you are probably using a database. Of course, the largest database you use is a search engine like Google or Yahoo. They index millions of webpages, which is how they can produce search results within seconds.

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