Examples
Examples are visible in plugin-based software such as some text editors and web browsers which often have people creating plugins that recreate software that would normally run on top of the operating system itself. The Firefox add-on mechanism has been used to develop a number of FTP clients and file browsers, which effectively replicate some of the features of the operating system, albeit on a more restricted platform.
In the database world, developers are sometimes tempted to bypass the RDBMS, for example by storing everything in one big table with three columns labelled entity ID, key, and value. While this entity-attribute-value model allows the developer to break out from the structure imposed by an SQL database, it loses out on all the benefits, since all of the work that could be done efficiently by the RDBMS is forced onto the application instead. Queries become much more convoluted, the indexes and query optimizer can no longer work effectively, and data validity constraints are not enforced. Performance and maintainability can be extremely poor.
A similar temptation exists for XML, where developers sometimes favor generic element names and use attributes to store meaningful information. For example, every element might be named item and have attributes type and value. This practice requires joins across multiple attributes in order to extract meaning. As a result, XPath expressions are more convoluted, evaluation is less efficient, and structural validation provides little benefit.
Another example is the phenomenon of web desktops, where a whole desktop environment—often including a web browser—runs inside a browser (which itself typically runs within the desktop environment provided by the operating system). A desktop within a desktop can be unusually awkward for the user, and hence this is generally only done to run programs that cannot easily be deployed on end user systems.
A concrete example comes from HAL, a hardware abstraction layer for Unix-like operating systems. It was a layer between the udev interface to kernel devices, and (mainly) desktop environments like KDE. After having been introduced with much effort, it is now considered deprecated, because it offered nearly no advantages over just using udev directly, but added much complexity from being convoluted and over-engineered.
Read more about this topic: Inner-platform Effect
Famous quotes containing the word examples:
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—G.C. (Georg Christoph)
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—André Breton (1896–1966)
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—Alexander Pope (1688–1744)