Web databases work differently than static databases, limited to one computer or a LAN network where the reference documents and other data does not change location. A web database is a dynamic website that indexes searchable information (either on the same website or to external web pages). Most web databases point to other sites. A typical web database will point to pages that have been deleted, altered or moved to another location. The creator or user of a web database has no control over the external pages referenced or linked to. Because of this non-static nature of the Internet, web database administrators attempt to keep on top of data changes and links to external pages. This is especially true with links to pages that have moved or vanished from the web. Metasites, which contain only links to other web sites, primarily search engines, tend to organize their databases in small hierarchies that provide links to other sites containing relevant data to a particular subject. These metasite web databases are organized around one subject, such as science, technology, news, games and other search engines. Another kind of metasite for web databases is a search engine site that runs multiple search engines. An example of this kind of web database is dogpile.com, which uses Google and other top search engines for random searches on the web.
Keeping Track of Data
Web databases store information in record and index structures. The record structure is visible to users, while the index structure is typically not available for users to browse. A number of web databases use artificial intelligence to handle updates to links. When a source of data moves to a new location on the Internet, the artificial intelligence changes the hyperlink’s address to match the new destination. Other web databases use link-checking programs that must be manually run by a web database administrator. Links to metasites, journals and other records are listed in the heading of most online databases. The difficulty with the information provided in these headings is that the links tend not to show when they were last updated. The web database’s main page typically displays the site having been updated the previous year. Check the subsidiary pages for a more accurate display of when web data and links have been updated. Use the information on the subsidiary pages for citing references in your research.
Systems and Languages
The most common web databases are MySQL, Oracle, Microsoft SQL Server, Postgre SQL, IBM DB2 and HSQLDB. The platforms web databases run on are Windows, Linux, Unix, and Solaris. Preprocessor hypertext (PHP) scripting language is used to create web databases (PHP runs on the server and not the browser). Learn to use PHP, because it enables web databases to run on multiple operating systems. PHP handles all requests from the web browser, so you won’t have to hassle with heavy hypertext markup language (HTML) when you create your web pages.