Help needed optimizing query - Mailing list pgsql-general

From Pedro Doria Meunier
Subject Help needed optimizing query
Date
Msg-id 1196342760.6912.8.camel@home-server-0
Whole thread Raw
Responses Re: Help needed optimizing query
List pgsql-general
Hi People.

I need some help optimizing this query:

SELECT u.friendly_name, distance(transform(u.curr_location,32628), rc.agg_geometry) AS thedistance, u.mobile
FROM (SELECT transform(collect(r.geometry),32628) AS agg_geometry, t.county FROM pt_madeira_roads r, pt_madeira_toponymy t
WHERE r.name ILIKE '%salão são roque%' AND t.county='Funchal' AND r.geometry && t.geometry GROUP BY t.county) rc, units AS u
WHERE expand(rc.agg_geometry,1000) && transform(u.curr_location,32628) AND u.customer_id='14' AND (u.even_code='A' OR u.even_code='B')
ORDER BY thedistance LIMIT 10;

Total query runtime: 1578 ms.
16 rows retrieved.

this is the explain analyze output:

"Limit  (cost=93.92..93.93 rows=1 width=78)"
"  ->  Sort  (cost=93.92..93.93 rows=1 width=78)"
"        Sort Key: distance(transform(u.curr_location, 32628), rc.agg_geometry)"
"        ->  Nested Loop  (cost=85.59..93.91 rows=1 width=78)"
"              Join Filter: (expand(rc.agg_geometry, 1000::double precision) && transform(u.curr_location, 32628))"
"              ->  HashAggregate  (cost=85.59..85.60 rows=1 width=226)"
"                    ->  Nested Loop  (cost=0.00..85.58 rows=1 width=226)"
"                          ->  Seq Scan on pt_madeira_toponymy t  (cost=0.00..2.74 rows=10 width=15770)"
"                                Filter: (county = 'Funchal'::text)"
"                          ->  Index Scan using pt_madeira_roads_idx on pt_madeira_roads r  (cost=0.00..8.27 rows=1 width=213)"
"                                Index Cond: (r.geometry && t.geometry)"
"                                Filter: ((r.name ~~* '%salão são roque%'::text) AND (r.geometry && t.geometry))"
"              ->  Index Scan using "units_customerID_idx" on units u  (cost=0.00..8.28 rows=1 width=46)"
"                    Index Cond: (customer_id = 14::bigint)"
"                    Filter: (((even_code)::text = 'A'::text) OR ((even_code)::text = 'B'::text))"

I still get Seq Scans although all used fields are indexed, hence the time used... :-(

Although this is almost 'targeted' to the beautiful SQL head of Regina's any input would be extremely appreciated... ;-)

Thank you!

--
Pedro Doria Meunier
Ips da Olaria
Edf. Jardins do Garajau, 4 r/c Y
9125-163 Caniço
Madeira
Portugal
GSM: +351 96 17 20 188 Skype: pdoriam
http://www.madeiragps.com
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