The text search engine allows queries to be formed from arbitrary Boolean expressions containing the keywords AND, OR, and NOT.
information retrieval: finds documents containing 'information' and 'retrieval'
information and retrieval: same as above
information or retrieval: finds documents containing either 'information' or 'retrieval'
information not retrieval: finds documents containing 'information' but not 'retrieval'
information near retrieval: finds documents where the two words a close to each other. The rank increases as word distance decreases.
Enclosing the search term(s) in double quotes will significantly improve search accuracy and return exact matches of the entire phrase.
For instance, searching for "information retrieval" within double quotes should return documents containing the exact phrase "information retrieval".