Hello, On Fri, Aug 18, 2017 at 03:30:38PM +0300, Aleksandr Parfenov wrote: > Hello hackers! > > I'm working on a new approach in text search configuration and want to > share my thought with community in order to get some feedback and maybe > some new ideas. >
There are several cases, where the new syntax could be useful: https://www.postgresql.org/message-id/4733b65a.9030...@students.mimuw.edu.pl Firstly check is lexeme stopword or not, and only then normalize it. https://www.postgresql.org/message-id/c6851b7e-da25-3d8e-a5df-022c395a11b4%40postgrespro.ru Support union of outputs of several dictionaries. https://www.postgresql.org/message-id/46D57E6F.8020009%40enterprisedb.com Support of chain of dictionaries using MAP BY operator. The basic idea of the approach is to bring to a user more control of text search configurations without writing additional or modifing existing dictionaries. > ALTER TEXT SEARCH CONFIGURATION en_de_search ADD MAPPING FOR asciiword, > word WITH > CASE > WHEN english_hunspell IS NOT NULL THEN english_hunspell > WHEN german_hunspell IS NOT NULL THEN german_hunspell > ELSE > -- stem dictionaries can't be used for language detection > english_stem UNION german_stem > END; For example, the configuration mentioned above will bring the following results: =# select d @@ q, d, q from to_tsvector('german_hunspell', 'Dieser Hund wollte ihn jedoch nicht nach Hause begleiten') d, to_tsquery('en_de_search', 'hause') q; ?column? | d | q ----------+----------------------------------------------+---------- t | 'begleiten':9 'hausen':8 'hund':2 'jedoch':5 | 'hausen' (1 row) This configuration is useful when a query language is unknown. Best regards, -- Arthur Zakirov Postgres Professional: http://www.postgrespro.com Russian Postgres Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
