On Fri, 1 Oct 2004, Kris Kiger wrote:
> Hey all, its me again. If I do not do a count(product_id) on my
> tsearch2 queries, its actually really fast, for example;
>
Hmm, I also really want to know what's the difference ?
Postgresql 8.0beta3 on Linux 2.4.25
tsearchd=# explain analyze select body from txt where fts_index @@ to_tsquery('oil') limit 1000;
QUERY PLAN
--------------------------------------------------------------------------------------------------------------------------------
Limit (cost=0.00..4027.67 rows=1000 width=315) (actual time=0.053..14.662 rows=1000 loops=1)
-> Index Scan using fts_idx on txt (cost=0.00..12083.02 rows=3000 width=315) (actual time=0.049..12.552 rows=1000
loops=1)
Index Cond: (fts_index @@ '\'oil\''::tsquery)
Total runtime: 15.848 ms
(4 rows)
tsearchd=# explain analyze select count(body) from txt where fts_index @@ to_tsquery('oil') limit 1000;
Didn't get result after 10 minutes :(
Regards,
Oleg
_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83