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Tsearch2 README File Example: Overview (Continued)

  • Stop words are not contained in the tsvector column type. Words like 'as', 'a', 'while', and 'is' are thrown out by the tsearch parser.
  • The default tsearch parser performs algorithimic word stemming. Words like 'query' and 'queries' are both stemmed as 'queri'. Searches on either word will match the other.
  • The tsvector type stores the location of a word stem. 'queri':10 is the 10th word in line 44, the first result returned by the query.
  • Boolean searches are supported. In 'database | query', the '|' operator means 'OR'. Other supported operators are '&' for 'AND' and '!' for 'NOT'.
  • The to_tsquery() function parses words into word stems. An optional parameter is the parser configuration to use. In this example, the 'default' parser is used.
  • The special operator '@@' is used to test for matches between a tsvector data type and a tsquery.
  • The headline function surrounds matching words by start and stop delimiters. The default delimiters are '<b>' and '</b>'.