Hello!
I rewrote my 4-tables join to use subselects:
SELECT DISTINCT subsec_id FROM positions WHERE pos_id IN (SELECT DISTINCT pos_id FROM central
WHEREshop_id IN (SELECT shop_id FROM shops WHERE distr_id IN (SELECT
distr_idFROM districts WHERE city_id = 2) ) )
;
This does not work, either - postgres loops forever, until I cancel
psql.
I splitted it - I ran
(SELECT DISTINCT pos_id FROM central WHERE shop_id IN (SELECT shop_id FROM shops
WHERE distr_id IN (SELECT distr_id FROM districts WHERE city_id =
2) ) )
and stored result in a file. Then I substituted the subselect with the
file:
SELECT DISTINCT subsec_id FROM positions WHERE pos_id IN
(1, 2, 3, 6, 22, 25, 26, 27, 28, 29, 31, 33, 34, 35, 38, 41, 42, 44, 45,
46, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 60, 61, 62, 63, 64)
and got desired result within a second.
This finally solves my problem, but I need to pass a long way to find
that postgres cannot handle such not too complex joins and subselects.
Oleg.
---- Oleg Broytmann http://members.xoom.com/phd2/ phd2@earthling.net Programmers don't die, they
justGOSUB without RETURN.