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to determine join order for tuning [message #345115]

Tue, 02 September 2008 06:21

trupti111
Messages: 29
Registered: August 2008
Location: navi mumbai

Junior Member

how to determine join order in where clause......and whether small table should be kept first or big table in from clause

What is driving table?

[Updated on: Tue, 02 September 2008 06:22]

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Re: to determine join order for tuning [message #345117 is a reply to message #345115]

Tue, 02 September 2008 06:24

Olivia
Messages: 519
Registered: June 2008

Senior Member

http://www.orafaq.com/faq/performance_tuning[/a]
Please go through the above link.

Regards,
Oli

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Re: to determine join order for tuning [message #345137 is a reply to message #345115]

Tue, 02 September 2008 06:55

trupti111
Messages: 29
Registered: August 2008
Location: navi mumbai

Junior Member

i have already checked this link but it is not specified there

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Re: to determine join order for tuning [message #345140 is a reply to message #345137]

Tue, 02 September 2008 07:04

Olivia
Messages: 519
Registered: June 2008

Senior Member

http://www.orafaq.com/tuningguide/
Problem and Fixes > MULTIPLE TABLE JOIN

[http://www.orafaq.com/tuningguide/five%20tables.html]

Regards,
Oli

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Re: to determine join order for tuning [message #345437 is a reply to message #345140]

Wed, 03 September 2008 10:32

JRowbottom
Messages: 5933
Registered: June 2006
Location: Sunny North Yorkshire, ho...

Senior Member

Why do you think you need to determine the join order?

If you want to see it, then look at the Explain Plan (visible in v$sql_plan, or from the Plan Table.

Unless you have a hint such as Leading, or Ordered, the order in which you list the tables makes no difference at all.

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Re: to determine join order for tuning [message #345855 is a reply to message #345437]

Fri, 05 September 2008 02:16

trupti111
Messages: 29
Registered: August 2008
Location: navi mumbai

Junior Member

I m talking about order in where clause
for eg suppose my query is
select * from a,b
where a.id = b.id

a is small table and b is big table

then writing a.id = b.id is good for reducing time
or b.id = a.id

[Updated on: Fri, 05 September 2008 04:25]

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