On Thu, 24 Mar 2005, Rick Jansen wrote:

Oleg Bartunov wrote:
from my notes

It's usefull to see words statistics, for example, to check how good
your dictionaries work or how did you configure pg_ts_cfgmap. Also, you
may notice probable stop words relevant for your collection. Tsearch
provides stat() function:


Don't hesitate to read it and if you find some bugs or know better wording
I'd be glad to improve my notes.

Thanks, but that stat() query takes way too long.. I let it run for like 4 hours and still nothing. The database I am testing tsearch2 on is also the production database (mysql) server so I have to be careful not to use too many resources :o

stat() is indeed a bigdog, it was designed for developers needs, so we recommend to save results in table.

Anyway, here's my pg_ts_cfgmap now (well the relevant bits):

default_english | lhword       | {en_ispell,en_stem}
default_english | lpart_hword  | {en_ispell,en_stem}
default_english | lword        | {en_ispell,en_stem}

Is it normal that queries for single words (or perhaps they are words
that are common) take a really long time? Like this:

'hispanic' isn't common, I see you get only 674 rows and 'buckingham & palace' returns 185 rows. Did you run 'vacuum analyze' ?
I see a big discrepancy between estimated rows (8041) and actual rows.

ilab=# explain analyze select count(*) from books where description_fti @@ to_tsquery('default', 'hispanic');
Aggregate (cost=20369.81..20369.81 rows=1 width=0) (actual time=261512.031..261512.031 rows=1 loops=1)
-> Index Scan using idxfti_idx on books (cost=0.00..20349.70 rows=8041 width=0) (actual time=45777.760..261509.288 rows=674 loops=1)
Index Cond: (description_fti @@ '\'hispan\''::tsquery)
Total runtime: 261518.529 ms
(4 rows)

ilab=# explain analyze select titel from books where description_fti @@ to_tsquery('default', 'buckingham & palace'); QUERY PLAN
Index Scan using idxfti_idx on books (cost=0.00..20349.70 rows=8041 width=57) (actual time=18992.045..48863.385 rows=185 loops=1)
Index Cond: (description_fti @@ '\'buckingham\' & \'palac\''::tsquery)
Total runtime: 48863.874 ms
(3 rows)

I dont know what happened, these queries were a lot faster 2 days ago..what the feck is going on?!


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

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