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* join query performance
@ 2008-03-08 04:07 petchimuthu lingam <spmlingam@gmail.com>
0 siblings, 1 reply; 3+ messages in thread
From: petchimuthu lingam @ 2008-03-08 04:07 UTC (permalink / raw)
To: pgsql-performance
In a select query i have used the join conditions, will it affect query
performance.
Explicitly I didn't used the join command, Will it make any difference.
My Query is:
SELECT test_log.test_id, test_log.test_id, test_log.test_id,
user_details.first_name, group_details.group_name, site_details.site_name,
test_projects.project_name, test_campaigns.campaign_name,
test_log.test_stime, test_log.test_duration, test_log.test_etime,
test_log.dialed_no, test_log.tester_id, test_log.voice_recorded,
test_log.screen_recorded, test_log.agent_id, test_log.group_id,
test_log.site_id, test_log.dtmf_values FROM
user_details,group_details,site_details,test_log,
sv_agent_map,test_campaigns,test_projects WHERE
sv_agent_map.sv_user_id='347' AND sv_agent_map.sv_group_id='13' AND
sv_agent_map.sv_site_id='10' AND
user_details.user_id=sv_agent_map.agent_user_id and
group_details.group_id=sv_agent_map.agent_group_id and
site_details.site_id=sv_agent_map.agent_site_id and
test_log.agent_id=sv_agent_map.agent_user_id and
test_log.campaign_id=test_campaigns.campaign_id and
test_projects.project_id=test_log.project_id ORDER BY test_log.test_id limit
5000.
The test_log has 50 million records.
The postgres version is 7.4
The Explain Analysis Output is:
QUERY PLAN
--------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit (cost=206342.52..206345.46 rows=1178 width=420) (actual time=
42514.526..42525.443 rows=5000 loops=1)
-> Sort (cost=206342.52..206345.46 rows=1178 width=420) (actual time=
42514.517..42519.466 rows=5000 loops=1)
Sort Key: test_log.test_id
-> Hash Join (cost=10.22..206282.43 rows=1178 width=420) (actual
time=1.297..37852.353 rows=281603 loops=1)
Hash Cond: ("outer".agent_id = "inner".user_id)
-> Hash Join (cost=7.11..206256.15 rows=2278 width=361)
(actual time=0.923..34630.591 rows=281603 loops=1)
Hash Cond: ("outer".campaign_id = "inner".campaign_id)
-> Hash Join (cost=5.77..206209.22 rows=2281
width=272) (actual time=0.789..31832.361 rows=281603 loops=1)
Hash Cond: ("outer".agent_group_id =
"inner".group_id)
-> Hash Join (cost=4.51..206153.11 rows=6407
width=228) (actual time=0.656..28964.197 rows=281603 loops=1)
Hash Cond: ("outer".project_id =
"inner".project_id)
-> Hash Join
(cost=3.24..206055.70rows=6415 width=139) (actual time=
0.461..26168.581 rows=281603 loops=1)
Hash Cond: ("outer".agent_id =
"inner".agent_user_id)
-> Seq Scan on test_log (cost=
0.00..180692.90 rows=5013690 width=83) (actual
time=0.005..18942.968rows=5061643 loops=1)
-> Hash (cost=3.24..3.24 rows=1
width=56) (actual time=0.362..0.362 rows=0 loops=1)
-> Hash Join
(cost=2.04..3.24rows=1 width=56) (actual time=
0.256..0.325 rows=31 loops=1)
Hash Cond:
("outer".site_id = "inner".agent_site_id)
-> Seq Scan on
site_details (cost=0.00..1.13 rows=13 width=52) (actual
time=0.005..0.018rows=13 loops=1)
-> Hash (cost=
2.03..2.03 rows=1 width=12) (actual time=0.156..0.156 rows=0 loops=1)
-> Seq Scan on
sv_agent_map (cost=0.00..2.03 rows=1 width=12) (actual
time=0.031..0.113rows=31 loops=1)
Filter:
((sv_user_id = 347) AND (sv_group_id = 13) AND (sv_site_id = 10))
-> Hash (cost=1.21..1.21 rows=21
width=97) (actual time=0.145..0.145 rows=0 loops=1)
-> Seq Scan on test_projects (cost=
0.00..1.21 rows=21 width=97) (actual time=0.010..0.042 rows=21 loops=1)
-> Hash (cost=1.21..1.21 rows=21 width=52)
(actual time=0.077..0.077 rows=0 loops=1)
-> Seq Scan on group_details (cost=
0.00..1.21 rows=21 width=52) (actual time=0.010..0.039 rows=21 loops=1)
-> Hash (cost=1.27..1.27 rows=27 width=97) (actual
time=0.084..0.084 rows=0 loops=1)
-> Seq Scan on test_campaigns
(cost=0.00..1.27rows=27 width=97) (actual time=
0.011..0.043 rows=27 loops=1)
-> Hash (cost=2.89..2.89 rows=89 width=67) (actual time=
0.245..0.245 rows=0 loops=1)
-> Seq Scan on user_details (cost=0.00..2.89 rows=89
width=67) (actual time=0.019..0.154 rows=89 loops=1)
Total runtime: 42548.932 ms
(30 rows)
--
With Best Regards,
Petchimuthulingam S
^ permalink raw reply [nested|flat] 3+ messages in thread
* join query performance
@ 2008-03-08 05:01 petchimuthu lingam <spmlingam@gmail.com>
parent: petchimuthu lingam <spmlingam@gmail.com>
0 siblings, 1 reply; 3+ messages in thread
From: petchimuthu lingam @ 2008-03-08 05:01 UTC (permalink / raw)
To: pgsql-php@postgresql.org
In a select query i have used the join conditions, will it affect query
performance.
Explicitly I didn't used the join command, Will it make any difference.
My Query is:
SELECT test_log.test_id, test_log.test_id, test_log.test_id,
user_details.first_name, group_details.group_name, site_details.site_name,
test_projects.project_name, test_campaigns.campaign_name,
test_log.test_stime, test_log.test_duration, test_log.test_etime,
test_log.dialed_no, test_log.tester_id, test_log.voice_recorded,
test_log.screen_recorded, test_log.agent_id, test_log.group_id,
test_log.site_id, test_log.dtmf_values FROM
user_details,group_details,site_details,test_log,
sv_agent_map,test_campaigns,test_projects WHERE
sv_agent_map.sv_user_id='347' AND sv_agent_map.sv_group_id='13' AND
sv_agent_map.sv_site_id='10' AND
user_details.user_id=sv_agent_map.agent_user_id and
group_details.group_id=sv_agent_map.agent_group_id and
site_details.site_id=sv_agent_map.agent_site_id and
test_log.agent_id=sv_agent_map.agent_user_id and
test_log.campaign_id=test_campaigns.campaign_id and
test_projects.project_id=test_log.project_id ORDER BY test_log.test_id limit
5000.
The test_log has 50 million records.
The postgres version is 7.4
The Explain Analysis Output is:
QUERY PLAN
--------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit (cost=206342.52..206345.46 rows=1178 width=420) (actual time=
42514.526..42525.443 rows=5000 loops=1)
-> Sort (cost=206342.52..206345.46 rows=1178 width=420) (actual time=
42514.517..42519.466 rows=5000 loops=1)
Sort Key: test_log.test_id
-> Hash Join (cost=10.22..206282.43 rows=1178 width=420) (actual
time=1.297..37852.353 rows=281603 loops=1)
Hash Cond: ("outer".agent_id = "inner".user_id)
-> Hash Join (cost=7.11..206256.15 rows=2278 width=361)
(actual time=0.923..34630.591 rows=281603 loops=1)
Hash Cond: ("outer".campaign_id = "inner".campaign_id)
-> Hash Join (cost=5.77..206209.22 rows=2281
width=272) (actual time=0.789..31832.361 rows=281603 loops=1)
Hash Cond: ("outer".agent_group_id =
"inner".group_id)
-> Hash Join (cost=4.51..206153.11 rows=6407
width=228) (actual time=0.656..28964.197 rows=281603 loops=1)
Hash Cond: ("outer".project_id =
"inner".project_id)
-> Hash Join
(cost=3.24..206055.70rows=6415 width=139) (actual time=
0.461..26168.581 rows=281603 loops=1)
Hash Cond: ("outer".agent_id =
"inner".agent_user_id)
-> Seq Scan on test_log (cost=
0.00..180692.90 rows=5013690 width=83) (actual
time=0.005..18942.968rows=5061643 loops=1)
-> Hash (cost=3.24..3.24 rows=1
width=56) (actual time=0.362..0.362 rows=0 loops=1)
-> Hash Join
(cost=2.04..3.24rows=1 width=56) (actual time=
0.256..0.325 rows=31 loops=1)
Hash Cond:
("outer".site_id = "inner".agent_site_id)
-> Seq Scan on
site_details (cost=0.00..1.13 rows=13 width=52) (actual
time=0.005..0.018rows=13 loops=1)
-> Hash (cost=
2.03..2.03 rows=1 width=12) (actual time=0.156..0.156 rows=0 loops=1)
-> Seq Scan on
sv_agent_map (cost=0.00..2.03 rows=1 width=12) (actual
time=0.031..0.113rows=31 loops=1)
Filter:
((sv_user_id = 347) AND (sv_group_id = 13) AND (sv_site_id = 10))
-> Hash (cost=1.21..1.21 rows=21
width=97) (actual time=0.145..0.145 rows=0 loops=1)
-> Seq Scan on test_projects (cost=
0.00..1.21 rows=21 width=97) (actual time=0.010..0.042 rows=21 loops=1)
-> Hash (cost=1.21..1.21 rows=21 width=52)
(actual time=0.077..0.077 rows=0 loops=1)
-> Seq Scan on group_details (cost=
0.00..1.21 rows=21 width=52) (actual time=0.010..0.039 rows=21 loops=1)
-> Hash (cost=1.27..1.27 rows=27 width=97) (actual
time=0.084..0.084 rows=0 loops=1)
-> Seq Scan on test_campaigns
(cost=0.00..1.27rows=27 width=97) (actual time=
0.011..0.043 rows=27 loops=1)
-> Hash (cost=2.89..2.89 rows=89 width=67) (actual time=
0.245..0.245 rows=0 loops=1)
-> Seq Scan on user_details (cost=0.00..2.89 rows=89
width=67) (actual time=0.019..0.154 rows=89 loops=1)
Total runtime: 42548.932 ms
(30 rows)
--
With Best Regards,
Petchimuthulingam S
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: join query performance
@ 2008-03-09 23:42 Chris <dmagick@gmail.com>
parent: petchimuthu lingam <spmlingam@gmail.com>
0 siblings, 0 replies; 3+ messages in thread
From: Chris @ 2008-03-09 23:42 UTC (permalink / raw)
To: petchimuthu lingam <spmlingam@gmail.com>; +Cc: pgsql-php@postgresql.org
petchimuthu lingam wrote:
>
> In a select query i have used the join conditions, will it affect query
> performance.
>
> Explicitly I didn't used the join command, Will it make any difference.
It'll make sure you don't miss any join conditions between two tables so
it'll be helpful in that respect, I didn't read your whole query but
with a 7 table join it's very easy to miss doing a match on one or more
tables.
It shouldn't take more than a couple of minutes to rewrite your query
and find out the answers..
--
Postgresql & php tutorials
http://www.designmagick.com/
^ permalink raw reply [nested|flat] 3+ messages in thread
end of thread, other threads:[~2008-03-09 23:42 UTC | newest]
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2008-03-08 04:07 join query performance petchimuthu lingam <spmlingam@gmail.com>
2008-03-08 05:01 ` petchimuthu lingam <spmlingam@gmail.com>
2008-03-09 23:42 ` Chris <dmagick@gmail.com>
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