Database search engine: Difference between revisions

Revision as of 00:49, 18 June 2015

Revision as of 15:20, 18 June 2015

Line 4:

=== Modern search engine components: ===

Searching for text-based content in [[databases]] or [[structured data]] formats (such as [[XML]], [[Comma-separated values|CSV]], etc.) presents special challenges and opportunities, which a number of specialized search engines resolve. Databases are slow when solving complex queries, which have multiple logical or [[string matching]] arguments. Databases allow logical queries, which full-text searchfor doesn'tinstance, the (use of multi-field [[boolean logic]] for- instance)which full-text searches don't. There"Crawling" is(a nohuman crawlingby-eye search) is not necessary forto find information stored in a database, since the data is already structured., Althoughalthough it is often necessary to index the data in a more compact form, that is designed to allow for faster searchsearches.

Database search engines were initially (and still usually are) included with major database software products. As such, they are usually called "indexing engines". However, these indexing engines are relatively limited in their ability to customize indexing formats (such as compounding, normalization, transformation, [[transliteration]], etc.). Usually they do not provide sophisticated data matching technology (such as [[string matching]], [[boolean logic]], algorithmic methods, search scripting, etc.).

In more advanced database search systems, relational databases are indexed by compounding multiple tables into a single table containing only the fields that need to be "queried" (or displayed in search results). The actual data -matching engines can include any functions, fromsuch as basic string matching, normalization, and transformation. Database search technology is heavily used by many large entities, such as government database services, e-commerce companies, web advertising platforms, telecommunications service providers, etc.

==See also==