Query Expansion Features

Query expansion modules allow you to define semantic query expansions to perform on prefix handlers. For example, if lemmatization was configured on the title prefix handler, and the user enters the query title:(mouse and man), the query expands to title:((mouse OR mice) and (man OR men)).

Wildcard search is a pattern-matching feature enabled by default. It allows you to find documents that include "test", "tests" and "tesselation" when searching on "tes*". Additional configuration is available to fine-tune your results.

Wildcard search is expanded using a dictionary generated from the corpus. See Configuring Dictionaries.

Spellcheck can be enabled to suggest alternate spellings for words in the query. Spell-check is much more effective if you first extract spell-check ngrams at index-time.

For details, see Adding 'Did You Mean?' Spell-Check.