https://forum.postgresql.org.pl/viewtopic.php?id=1184 Thu, 15 Dec 2011 16:05:11 +0000 PunBB https://forum.postgresql.org.pl/viewtopic.php?pid=3322#p3322 0 And rok = 2012 And id_tab3 = 8 Group By id_tab2;[/code] Ew. możesz użyć distincta (w wersji, której używam teraz tj. 8.1 robi dodatkowo iimplicit sortowanie), poniżej porównanie dla 100 000 losowych wierszy: [code]Explain Analyze Select Distinct id_tab2 From tab1 Where suma1 + suma2 + suma3 > 0 And rok = 2012 And id_tab3 = 8; QUERY PLAN -------------------------------------------------------------------------------------------------------------------- Unique (cost=32898.61..32898.65 rows=1 width=4) (actual time=585.861..599.229 rows=21 loops=1) -> Sort (cost=32898.61..32898.63 rows=9 width=4) (actual time=585.858..594.046 rows=28907 loops=1) Sort Key: id_tab2 -> Seq Scan on tab1 (cost=0.00..32898.46 rows=9 width=4) (actual time=0.039..518.839 rows=28907 loops=1) Filter: ((((suma1 + suma2) + suma3) > 0) AND (rok = 2012) AND (id_tab3 = 8)) Total runtime: 599.917 ms (6 rows) Explain Analyze Select id_tab2 From tab1 Where suma1 + suma2 + suma3 > 0 And rok = 2012 And id_tab3 = 8 Group By id_tab2 Order by id_tab2; QUERY PLAN -------------------------------------------------------------------------------------------------------------------- Sort (cost=32898.51..32898.51 rows=1 width=4) (actual time=527.562..527.564 rows=21 loops=1) Sort Key: id_tab2 -> HashAggregate (cost=32898.49..32898.50 rows=1 width=4) (actual time=527.532..527.539 rows=21 loops=1) -> Seq Scan on tab1 (cost=0.00..32898.46 rows=9 width=4) (actual time=0.037..517.137 rows=28907 loops=1) Filter: ((((suma1 + suma2) + suma3) > 0) AND (rok = 2012) AND (id_tab3 = 8)) Total runtime: 527.613 ms (6 rows) Explain Analyze Select id_tab2 From tab1 Where suma1 + suma2 + suma3 > 0 And rok = 2012 And id_tab3 = 8 Group By id_tab2; QUERY PLAN -------------------------------------------------------------------------------------------------------------- HashAggregate (cost=32898.49..32898.50 rows=1 width=4) (actual time=526.200..526.207 rows=21 loops=1) -> Seq Scan on tab1 (cost=0.00..32898.46 rows=9 width=4) (actual time=0.039..515.914 rows=28907 loops=1) Filter: ((((suma1 + suma2) + suma3) > 0) AND (rok = 2012) AND (id_tab3 = 8)) Total runtime: 526.250 ms (4 rows)[/code]]]> Thu, 15 Dec 2011 16:05:11 +0000 https://forum.postgresql.org.pl/viewtopic.php?pid=3322#p3322 https://forum.postgresql.org.pl/viewtopic.php?pid=3321#p3321 0 where (przykładowo) rok = 2012 and id_tab3=8]]> Thu, 15 Dec 2011 11:46:36 +0000 https://forum.postgresql.org.pl/viewtopic.php?pid=3321#p3321