postgresql/contrib/fuzzystrmatch/fuzzystrmatch.sql.in

CREATE FUNCTION levenshtein (text,text) RETURNS int
  AS 'MODULE_PATHNAME','levenshtein' LANGUAGE 'c' with (iscachable, isstrict);

CREATE FUNCTION metaphone (text,int) RETURNS text
  AS 'MODULE_PATHNAME','metaphone' LANGUAGE 'c' with (iscachable, isstrict);
Per this discussion, here's a patch to implement both levenshtein() and metaphone() in a contrib. There seem to be a fair number of different approaches to both of these algorithms. I used the simplest case for levenshtein which has a cost of 1 for any character insertion, deletion, or substitution. For metaphone, I adapted the same code from CPAN that the PHP folks did. A couple of questions: 1. Does it make sense to fold the soundex contrib together with this one? 2. I was debating trying to add multibyte support to levenshtein (it would make no sense at all for metaphone), but a quick search through the contrib directory found no hits on the word MULTIBYTE. Should worry about adding multibyte support to levenshtein()? Joe Conway 2001-08-08 00:47:43 +08:00			`CREATE FUNCTION levenshtein (text,text) RETURNS int`
			`AS 'MODULE_PATHNAME','levenshtein' LANGUAGE 'c' with (iscachable, isstrict);`

			`CREATE FUNCTION metaphone (text,int) RETURNS text`
			`AS 'MODULE_PATHNAME','metaphone' LANGUAGE 'c' with (iscachable, isstrict);`