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
with
both 'information' and 'retrieval'
- information not
retrieval - finds documents containing
'information' but not 'retrieval'
- (information not
retrieval) and WAIS -
documents containing
'WAIS', plus 'information' but not 'retrieval'
- web* -
finds documents containing
words starting with 'web'