|
A '''database search engine''' is a [[search engine]] that operates on material stored in a digital [[database]].
{{copyedit|date=June 2015}}
Categories of [[search engine]] software include: Web search or full-text search (example: [[Lucene]]), database or structured data search (example: [[Diesel point]]), and mixed or [[enterprise search]] (example: [[Google Search Appliance]]). The largest web internet directories, such as [[Google]] and [[Yahoo!]], utilize hundreds of thousands of computers to process billions of webpages and return results for thousands of searches per second (not search engines). High volumes of queries and text processing require the software to run in a highly distributed environment with a high degree of redundancy.
== Search engines ==
Modern search engines have the following main components:
Categories of search engine software include:
Searching for text-based content in [[databases]] or other [[structured data]] formats ([[XML]], [[Comma-separated values|CSV]], etc.) presents some special challenges and opportunities which a number of specialized search engines resolve. Databases are slow when solving complex queries (with multiple logical or [[string matching]] arguments. Databases allow logical queries, which full-text search doesn't (use of multi-field boolean logic for instance). There is no crawling necessary for a database, since the data is already structured, but it is often necessary to index the data in a more compact form designed to allow for faster search. ▼* Web search or full-text search (e.g. [[Lucene]]).
* [[Database]] or [[structured data]] search (e.g. [[Dieselpoint]]).
* Mixed or [[enterprise search]] (e.g. [[Google Search Appliance]]).
The largest online directories, such as [[Google]] and [[Yahoo]], utilize thousands of computers to process billions of website documents using [[web crawlers]] or [[spiders (software)]], returning results for thousands of searches per second. Processing high query volumes requires software to run in a distributed environment with redundancy.
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 (compounding, normalization, transformation, [[transliteration]], etc.) Usually they do not provide sophisticated data matching technology ([[string matching]], [[boolean logic]], algorithmic methods, search scripting, etc.).
== Components ==
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 from basic string matching, normalization, and transformation. Database search technology is heavily used by government database services, e-commerce companies, web advertising platforms, telecommunications service providers, etc.
▲Searching for text-basedtextual content in [[databases]] or other [[structured data]] formats ( such as [[XML]] , and [[Comma-separated values|CSV]] , etc.) presents some special challenges and opportunities which a number of specialized search engines resolve. [[Databases ]] areallow slowlogical whenqueries solvingsuch complexas queriesthe (withuse multipleof logical ormulti-field [[ stringBoolean matchinglogic]] arguments. Databases allow logical queries, whichwhile full-text searchsearches doesn'tdo not. "Crawling" ( usea ofhuman multiby- fieldeye booleansearch) logicis fornot instance).necessary to Therefind isinformation nostored crawling necessary forin a database , sincebecause the data is already structured ,. but[[index it is often necessary to index(database)|Indexing]] the data in a more compact form designed to allowallows for faster searchsearches.
Database search engines are usually included with major database software products.
== Applications ==
Database search technology is used by large public and private entities including government database services, e-commerce companies, online advertising platforms, telecommunications service providers and other consumers with a need to access information in large repositories.
==See also==
*[[Outline of search engines]]
*[[Search engine]]
*[[WebList crawlerof search engines]]
*[[Search engine indexing]]
*[[Enterprise search]]
==External links==
| 