Glossary

Full-Text Search

Full-text search is searching over natural language text with support for relevance, morphology, stop words, and result ranking. Unlike a LIKE search: LIKE '%php%' ignores morphology and does not rank; full-text search does both.

MySQL FULLTEXT

MySQL supports FULLTEXT indexes for MyISAM and InnoDB. Two modes: BOOLEAN (operators +, -, *) and NATURAL LANGUAGE (relevance ranking).

MATCH(title, body) AGAINST('opcache php' IN BOOLEAN MODE)

Elasticsearch and OpenSearch

For serious search — dedicated Lucene-based engines. They support stemming, faceted search, synonyms, typo-tolerance, and geo-search. Data is synchronised from the main DB via events.