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Query optimization [message #128227]

Fri, 15 July 2005 17:37

Hina
Messages: 51
Registered: April 2004

Member

How to optimize following query?

SELECT analyst_id,
       employee employee_name
FROM   employee_alias
WHERE  indicator = 'F'
UNION
SELECT analyst_id,
       employee_name
FROM   employee
/

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Re: Query optimization [message #128235 is a reply to message #128227]

Fri, 15 July 2005 22:56

Frank Naude
Messages: 4581
Registered: April 1998

Senior Member

Read the Oracle Performance Tuning Guide, especially the sections about Optimizing SQL Statements and how to do a simple Explain Plan.

Best regards.

Frank

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Re: Query optimization [message #128238 is a reply to message #128235]

Fri, 15 July 2005 23:47

Hina
Messages: 51
Registered: April 2004

Member

Hi Frank,

I already tried, but could not find a solution that's why I posted on this forum.

Regards

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Re: Query optimization [message #128256 is a reply to message #128238]

Sat, 16 July 2005 04:06

Frank Naude
Messages: 4581
Registered: April 1998

Senior Member

Yes, that is why you need to read the Performance Tuning Guide. It will enable you to do an explain plan and get some execution statistics. Without it, you would not know what's happening, nor will anyone else be able to help you.

Best regards.

Frank

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