{ "content": "

INDEXING<\/a><\/h1>

INDEXING<\/a> is a fundamental technique in COMPUTER-SCIENCE<\/a> used to speed up the retrieval of records from a dataset. In DATABASE-MANAGEMENT-SYSTEMS<\/a>, an index is a data structure that improves the speed of data retrieval operations on a database table at the cost of additional storage and slower writes. For more on the basics, see Wikipedia's entry on Database Indexing<\/a>.<\/p>

Methodologies and Structures<\/h2>

Common indexing structures include the B-TREE<\/a>, which is widely used in RELATIONAL-DATABASES<\/a> like MYSQL<\/a> and POSTGRESQL<\/a>. Another approach is HASH-INDEXING<\/a>, which is efficient for equality comparisons. Advanced systems might use a BITMAP-INDEX<\/a> for columns with low cardinality. Technical implementation details are provided by the Oracle Documentation<\/a>.<\/p>

Web and Search Applications<\/h2>

In the context of the web, SEARCH-ENGINE-INDEXING<\/a> is the process of a search engine collecting and storing data for use in search results. This involves CRAWLING<\/a> the web and creating an INVERTED-INDEX<\/a>. This allows engines like GOOGLE<\/a> to provide results in milliseconds. Guidance on how this affects SEARCH-ENGINE-OPTIMIZATION<\/a> can be found at Google Search Central<\/a>.<\/p>