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Different Explain in Different Instances. [message #258625] Mon, 13 August 2007 03:51 Go to next message
maggy_ashee
Messages: 70
Registered: May 2007
Member
Hi all,

when am trying to run a query in my test instance it runs faster and the cost is just '7000' but when i run the same query in another instance the cost is '64000'.

The explain plan is extremely different.Different Indexes are being used.Can any one help me out in this,plz this some wat urgent?

The version and all are one and the same.

Thanks in Advance.
Re: Different Explain in Different Instances. [message #258626 is a reply to message #258625] Mon, 13 August 2007 03:53 Go to previous messageGo to next message
rons
Messages: 18
Registered: June 2007
Location: Scottland
Junior Member
Hi,

May be gathering stats will help.

Ronald.
Re: Different Explain in Different Instances. [message #258630 is a reply to message #258626] Mon, 13 August 2007 03:55 Go to previous messageGo to next message
maggy_ashee
Messages: 70
Registered: May 2007
Member
Please let me know how to do that ?
Re: Different Explain in Different Instances. [message #258632 is a reply to message #258625] Mon, 13 August 2007 03:57 Go to previous messageGo to next message
Michel Cadot
Messages: 64103
Registered: March 2007
Location: Nanterre, France, http://...
Senior Member
Account Moderator
Quote:
plz this some wat urgent?

Nothing is urgent in forum but you to read the sticky and don't use IM speak.

Regards
Michel

[Updated on: Mon, 13 August 2007 03:57]

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Re: Different Explain in Different Instances. [message #258633 is a reply to message #258625] Mon, 13 August 2007 03:58 Go to previous messageGo to next message
rons
Messages: 18
Registered: June 2007
Location: Scottland
Junior Member
Hi,

Please check this.

Ronald.
Re: Different Explain in Different Instances. [message #258686 is a reply to message #258633] Mon, 13 August 2007 06:28 Go to previous messageGo to next message
maggy_ashee
Messages: 70
Registered: May 2007
Member
If the cost has got reduced ,can we be sure that the performance has been improved.

Because in some cases I see that even the cost get reduced the performance is still worse.
Re: Different Explain in Different Instances. [message #258693 is a reply to message #258686] Mon, 13 August 2007 06:48 Go to previous messageGo to next message
pablolee
Messages: 2834
Registered: May 2007
Location: Scotland
Senior Member
maggy_ashee wrote on Mon, 13 August 2007 12:28
If the cost has got reduced ,can we be sure that the performance has been improved.

Because in some cases I see that even the cost get reduced the performance is still worse.

Not to be facetious, but your second statement seems to answer your first Smile
Re: Different Explain in Different Instances. [message #258759 is a reply to message #258693] Mon, 13 August 2007 09:35 Go to previous message
maggy_ashee
Messages: 70
Registered: May 2007
Member
It was my doubt?noting to be facetious Laughing

ok fin

Gather statistics is being done for all the tables periodically.
Can you suggest some other way to rectify the said problem.?
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