Re: optimizing query ..

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#637

From: Wayne Niddery [TeamB]
Date: Mon, 17 Sep 2007 14:28

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Karol Bieniaszewski wrote:
>
>> I would try this:
>>
>> FROM
>> TABLE_C C
>> INNER JOIN TABLE_A A ON A.ID=C.ID_OBJ
>> INNER JOIN TABLE_B B ON B.ID_OBJ=C.ID_OBJ AND B.SYSTEM=C.SYSTEM
>> LEFT JOIN TABLE_D D ON D.NAZWA=C.ALARM
>> WHERE
>> C.ZRODLO=:PARAM_X
>> AND B.KOD=:PARAM_Y
>> AND B.SYSTEM=:PARAM_Z
>
> now plan is :(
> PLAN JOIN (JOIN (A NATURAL,C INDEX (IXA_TABLE_C__OBJ__ZRO__SYS),B
> INDEX (IXA_TABLE_B__KOD__SYSTEM, FK_TABLE_B__ID_OBJ)),D INDEX
> (IXAU__TABLE_D__NAZWA))

You could try making A a left join. If there is always a match, the result 
set will be the same, if there could be C's without a matching A then add a 
condition to the where clause : ' A.ID is not null'.

-- 
Wayne Niddery - Winwright, Inc (www.winwright.ca)
"At the apex of every great tragedy of mankind there stands the figure
of an incorruptible altruist." - Ayn Rand

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Subject: Re: optimizing query ..
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