Re: Optimizing query

From: "Pierre C" <lists(at)peufeu(dot)com>
To: pgsql-performance(at)postgresql(dot)org, pasman pasmański <pasman(dot)p(at)gmail(dot)com>
Subject: Re: Optimizing query
Date: 2010-11-26 09:46:11
Message-ID: op.vmruq9jseorkce@apollo13
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Note that your LEFT JOIN condition is probably quite slow...

Please post EXPLAIN ANALYZE for this simplified version :

SELECT
R."Osoba weryfikuj?ca",
R."LP",
A."NKA",
A."NTA",
Sum("Ile")
FROM "NumeryA" A
LEFT JOIN "Rejestr stacji do naprawy" R ON (
A."NKA" = R."Numer kierunkowy"
and A."NTA" like R."Numer stacji"
and substr(A."NTA",1,5) = substr(R."Numer stacji",1,5)
)
WHERE
A."DataPliku" >= current_date-4*30
and A."KodB??du"=74::text
and R."Data weryfikacji" >= current_date-4*30
GROUP BY R."Osoba weryfikuj?ca",R."LP",A."NKA", A."NTA"
ORDER BY Sum("Ile") DESC
LIMIT 5000

And also post EXPLAIN ANALYZE for this :

SELECT
A."NKA",
A."NTA",
Sum("Ile") AS ss -- if it's in this table
FROM "NumeryA" A
WHERE
A."DataPliku" >= current_date-4*30
and A."KodB??du"=74::text
GROUP BY A."NKA", A."NTA"

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