On Thu, 12 Feb 2009, Tom Lane wrote:
Gordon Callan <gordon_callan@xxxxxxxxxxx> writes:
Next we create an index on the ts_vector column:
CREATE INDEX node_ts_body on node USING gin(ts_body);
From the documentation, it seems this index will know what config each row has.
No, actually the index doesn't know and doesn't care. The tsvector
representation is language-independent --- it contains "just strings".
All the language-dependent processing happens during reduction of the
document text to tsvector (or reduction of a search string to tsquery).
So if words from different languages happen to reduce to the same
string, searches in both languages will find that entry.
Usually this works the way people want; but if not, you could add an
additional WHERE condition to your queries to match only documents in
the desired language.
contrib/btree_gin, which is under review for 8.4, will allow to create
composite index like (ts_config, tsvector), so queries which specified
ts_config (language) will uses this index.
Regards,
Oleg
_____________________________________________________________
Oleg Bartunov, Research Scientist, Head of AstroNet (www.astronet.ru),
Sternberg Astronomical Institute, Moscow University, Russia
Internet: oleg@xxxxxxxxxx, http://www.sai.msu.su/~megera/
phone: +007(495)939-16-83, +007(495)939-23-83
--
Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general
