Re: [SQL] problem with slow select
thank you for answer and excuse me for later
this is query plan:
QUERY PLAN
---
Nested Loop (cost=10564.42..10853.74 rows=1 width=150) (actual
time=11626.89..12060.36 rows=6 loops=1)
-> Merge Join (cost=10564.42..10820.69 rows=6 width=131) (actual
time=11626.45..12058.84 rows=6 loops=1)
Merge Cond: (("outer".idcode = "inner".idcode) AND
("outer".time = "inner".time))
-> Sort (cost=7550.07..7675.40 rows=50134 width=104) (actual
time=8910.91..9031.23 rows=49293 loops=1)
Sort Key: .idcode, .time
-> Seq Scan on (cost=0.00..1586.34 rows=50134
width=104) (actual time=0.10..852.78 rows=50515 loops=1)
-> Sort (cost=3014.35..3017.11 rows=1102 width=31) (actual
time=2419.43..2419.45 rows=6 loops=1)
Sort Key: temptable.idcode, temptable.time
-> Subquery Scan temptable (cost=2876.08..2958.70
rows=1102 width=31) (actual time=2154.84..2419.15 rows=6 loops=1)
-> Aggregate (cost=2876.08..2958.70 rows=1102
width=31) (actual time=2154.83..2419.10 rows=6 loops=1)
-> Group (cost=2876.08..2931.16 rows=11016
width=31) (actual time=2066.58..2389.91 rows=19486 loops=1)
-> Sort (cost=2876.08..2903.62
rows=11016 width=31) (actual time=2066.55..2106.39 rows=19486 loops=1)
Sort Key: .idcode
-> Hash Join
(cost=36.50..2136.54 rows=11016 width=31) (actual time=3.41..765.49
rows=19486 loops=1)
Hash Cond: ("outer".idcode
= "inner".idcode)
-> Seq Scan on
(cost=0.00..1586.34 rows=50134 width=21) (actual time=0.12..301.87
rows=50515 loops=1)
-> Hash
(cost=36.48..36.48 rows=7 width=10) (actual time=3.10..3.10 rows=0
loops=1)
-> Seq Scan on
(cost=0.00..36.48 rows=7 width=10) (actual time=0.13..3.04 rows=6
loops=1)
Filter:
((idazien = 8::numeric) OR (idazien = 1019::numeric))
-> Index Scan using _pkey on (cost=0.00..5.46 rows=1
width=19) (actual time=0.17..0.18 rows=1 loops=6)
Index Cond: (.idcode = "outer".idcode)
Filter: ((idazien = 8::numeric) OR (idazien = 1019::numeric))
Total runtime: 12065.05 msec
(23 rows)
--
francescosaf
Posted via http://www.webservertalk.com
View this thread: http://www.webservertalk.com/message189539.html
---(end of broadcast)---
TIP 4: Don't 'kill -9' the postmaster
[SQL] problem with slow select
hi I have two tables: table: idcode varchar(15) -->references (idcode) table latitude float longitude float time timestamp p_a char(1) barcode address idprog serial... -->primary key flag boolean table idfact numeric(7,0) --->references . idcode varchar(15) --->primary key name varchar(20) I want to exctract the last operation of table for each idcode of table where idfact=123 I HAVE THIS QUERY BUT IT IS TOO SLOW (10 SECONDS): select .*,.name from , join (select .idcode,max(.tempo) as tempo from , where .idfact=123 and .idcode=.idcode group by .idcode) temptable on (temptable.tempo=.tempo and temptable.idcode=.idcode) where .idfact=123 and .idcode=.idcode order by .name; PLEASE HELP ME -- francescosaf Posted via http://www.webservertalk.com View this thread: http://www.webservertalk.com/message189539.html ---(end of broadcast)--- TIP 8: explain analyze is your friend
