On the fly

From Wikipedia, the free encyclopedia

This article or section does not cite its references or sources.
Please help improve this article by introducing appropriate citations. (help, get involved!) This article has been tagged since September 2006.

Look up On the fly in
Wiktionary, the free dictionary.

In colloquial use, on the fly means in a hurry, generally involving haste or carelessness.

In relation to computing, on the fly describes activities that develop or occur dynamically rather than as the result of something that is statically predefined.

For example, the content of a page that is sent to the user from a Web site can be developed (and varied) "on the fly" based on dynamic factors such as the time of day, what pages the user has looked at previously, and specific user input.

As an example of the latter, user input may be a search item; it would not be practical to store all possible result pages, although the database may be indexed to make the search faster.

The Web server calls a program to produce the "on-the-fly" page that is to be returned. There are several techniques for on-the-fly page development, including the server side, the use of cookies (information previously stored about a user that is located in a special file on his/her hard disk), Microsoft's Active Server Pages, and PHP.

A page created on the fly may or may not have its own URL, containing all data on which the page depends.

[edit] Computer storage

On-the-fly is also a term used for copying a source medium (i.e. CD-ROM or DVD) to a target medium (i.e. CD-R) directly, without first saving the source on an intermediate medium (i.e. a harddisk).