Re: TSearch2 and optimisation ...

Josh,

Le Jeudi 26 Août 2004 01:50, Josh Berkus a écrit :
> > The request takes about 4 seconds ... I have about 1 400 000 records in
> > article and 36 000 records in site table ... it's a Bi-Pentium III 933
> > MHz server with 1 Gb memory ... I'm using Postgresql 7.4.5
> > For me this result is very very slow I really need a quicker result with
> > less than 1 second ...
> > The next time I call the same request I have got the result in 439 ms ...
> > but If I replace "Postgresql" in my find with "Linux" for example I will
> > get the next result in 5 seconds ... :o(
>
> Hmmm. It sounds like your system is unable to keep all of the data cached
> in memory. What else do you have going on on that machine?

There is an Apache + PHP running in same time ...

> > Explain gives me this result :
>
> Please do "EXPLAIN ANALYZE" so that we can see where time is actually
> spent.

QUERY PLAN
---------------------------------------------------------------------------------------------------------------------------
Sort (cost=10740.35..10743.73 rows=1351 width=190) (actual
time=7054.603..7054.707 rows=139 loops=1)
Sort Key: rank(a.idxfti, '\'postgresql\''::tsquery), a.r_date
-> Merge Join (cost=4123.09..10670.10 rows=1351 width=190) (actual
time=5476.749..7052.766 rows=139 loops=1)
Merge Cond: ("outer".id_site = "inner".id_site)
-> Index Scan using site_id_site_key on site s (cost=0.00..2846.52
rows=35705 width=28) (actual time=43.985..1548.903 rows=34897 loops=1)
-> Sort (cost=4123.09..4126.47 rows=1351 width=166) (actual
time=5416.836..5416.983 rows=139 loops=1)
Sort Key: a.id_site
-> Index Scan using idxfti_idx on article a
(cost=0.00..4052.84 rows=1351 width=166) (actual time=109.766..5415.108
rows=139 loops=1)
Index Cond: (idxfti @@ '\'postgresql\''::tsquery)
Filter: (idxfti @@ '\'postgresql\''::tsquery)
SubPlan
-> Seq Scan on user_choice u (cost=0.00..2.69 rows=1 width=4)
(actual time=0.146..0.146 rows=0 loops=139)
Filter: ((id_site = $0) AND (id_user = 1))
Total runtime: 7056.126 ms

Thanks for your help ...
--
Hervé Piedvache

Elma Ingénierie Informatique
6 rue du Faubourg Saint-Honoré
F-75008 - Paris - France
Pho. 33-144949901
Fax. 33-144949902