2011/1/17 Zotov <zo...@oe-it.ru>: > It`s just a sample. > > select c.id from OneRow c join abstract a on a.id=AsInteger(c.id) > > "Nested Loop (cost=0.00..786642.96 rows=1 width=4) (actual > time=91021.167..119601.344 rows=1 loops=1)" > " Join Filter: ((a.id)::integer = asinteger((c.id)::integer))" > " -> Seq Scan on onerow c (cost=0.00..1.01 rows=1 width=4) (actual > time=0.007..0.008 rows=1 loops=1)" > " -> Seq Scan on abstract a (cost=0.00..442339.78 rows=22953478 width=4) > (actual time=0.003..115193.283 rows=22953478 loops=1)" > "Total runtime: 119601.428 ms" > > > select c.id from OneRow c join abstract a on a.id=c.id > > "Nested Loop (cost=0.00..13.85 rows=1 width=4) (actual > time=254.579..254.585 rows=1 loops=1)" > " -> Seq Scan on onerow c (cost=0.00..1.01 rows=1 width=4) (actual > time=0.006..0.007 rows=1 loops=1)" > " -> Index Scan using integ_1197 on abstract a (cost=0.00..12.83 rows=1 > width=4) (actual time=254.559..254.563 rows=1 loops=1)" > " Index Cond: ((a.id)::integer = (c.id)::integer)" > "Total runtime: 254.648 ms" > > > OneRow Contains only one row, > abstract contains 22 953 500 rows > > AsInteger is simple function on Delphi > it just return input value > > CREATE OR REPLACE FUNCTION asinteger(integer) > RETURNS integer AS > 'oeudfpg.dll', 'AsInteger' > LANGUAGE c VOLATILE > COST 1;
are you sure so your function needs a VOLATILE flag? Regards Pavel Stehule > > > Why SeqScan??? > > this query is simple sample to show SLOW seq scan plan > I have a real query what i don`t know when it will be done... but at > firebird this query with full fetch 1-2 minutes > I can`t give you this real query and database (database size is more, than > 20 GB) > as i see that query have same problem as this sample > It`s so sad, because I spend so much time to support posgtresql in my > project and now i see what more queries is slower more than 10 times... > Please HELP! > > PostgreSQL version 9.0.2 > > -- > С уважением, > Зотов Роман Владимирович > руководитель Отдела инструментария > ЗАО "НПО Консультант" > г.Иваново, ул. Палехская, д. 10 > тел./факс: (4932) 41-01-21 > mailto: zo...@oe-it.ru -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
