I've tried to use Dan Tow's tuning method and
created all the right indexes from his diagraming method, but the query still
performs quite slow both inside the application and just inside pgadmin
III. Can anyone be kind enough to help me tune it so that it performs
better in postgres? I don't think it's using the right indexes, or maybe
postgres needs special treatment.
I've converted the below query to SQL from a
Hibernate query, so the syntax is probably not perfect but it's semantics
are exactly the same. I've done so by
looking at the source code, but I can't run it to get the exact SQL since I
don't have the database on my home machine.
select s.*
from shipment s inner join carrier_code cc on s.carrier_code_id = cc.id inner join carrier c on
cc.carrier_id = c.id
inner join carrier_to_person ctp
on ctp.carrier_id = c.id
inner join person p on p.id =
ctp.person_id
inner join shipment_status cs on
s.current_status_id = cs.id
inner join release_code rc on
cs.release_code_id = rc.id
left join shipment_status ss on
ss.shipment_id = s.id
where p.id = :personId and s.is_purged = false and rc.number = '9' and cs is not null and cs.date >= current_date - 31 order by cs.date desc Just assume I have no indexes for the moment
because while some of the indexes I made make it work faster, it's still around
250 milliseconds and under heavy load, the query performs very badly (6-7
seconds).
For your information:
shipment contains 40,000 rows
shipment_status contains 80,000 rows
release_code contains 8 rows
person contains 300 rows
carrier contains 60 rows
carrier_code contains 70 rows
The filter ratios are:
rc.number = '9' (0.125)
cs.date >= current_date - 31 (.10)
p.id = ? (0.003)
s.is_purged = false (.98)
I really hope someone can help since I'm pretty
much stuck.
Best regards and many thanks,
Ken
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- [PERFORM] Help with tuning this query Ken Egervari
- Re: [PERFORM] Help with tuning this query Richard Huxton
- Re: [PERFORM] Help with tuning this query Bricklen Anderson
- Re: [PERFORM] Help with tuning this query Bruce Momjian
- Re: [PERFORM] Help with tuning this query John Arbash Meinel
- Re: [PERFORM] Help with tuning this query Ken Egervari
- Re: [PERFORM] Help with tuning this query John Arbash Meinel
- Re: [PERFORM] Help with tuning this query Ragnar Hafstaư
- Re: [PERFORM] Help with tuning this query Ken Egervari
- Re: [PERFORM] Help with tuning this query Ragnar Hafstaư
- Re: [PERFORM] Help with tuning this qu... Ken Egervari