The text search engine allows queries to be formed from arbitrary Boolean expressions containing the keywords AND, OR, and NOT, and grouped with parentheses.
For
example:
information
retrieval
finds
documents containing 'information' or 'retrieval'
information
or retrieval
same
as above
information
and retrieval
finds
documents containing both 'information' and 'retrieval'
information
not retrieval
finds
documents containing 'information' but not 'retrieval'
(information
not retrieval) and WAIS
finds
documents containing 'WAIS', plus 'information' but not 'retrieval'
web*
finds
documents containing words starting with 'web'