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SQL tuning [message #1241]

Sun, 14 April 2002 21:33

Reddy Ashok Venkat Trinad
Messages: 4
Registered: April 2002

Junior Member

How does the FROM and WHERE clause change the performance?

I mean the order of the tables in FROM clause and conditions in WHERE clause can affect the performance.How and Why?

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Re: SQL tuning [message #1246 is a reply to message #1241]

Sun, 14 April 2002 22:25

Satish Shrikhande
Messages: 167
Registered: October 2001

Senior Member

Use
-- the smallest table at last in the FROM
-- the largest row table at last in WHERE condition .

Satish Shrikhande

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Re: SQL tuning [message #1251 is a reply to message #1246]

Mon, 15 April 2002 03:28

Satish Shrikhande
Messages: 167
Registered: October 2001

Senior Member

Thank u.

But in case where u do not know which table may retrieve less number of rows or not?what to do?

Also why do we use this way?can u pls reply detailed on this

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Re: SQL tuning [message #1265 is a reply to message #1246]

Mon, 15 April 2002 22:22

Reddy Ashok Venkat Trinad
Messages: 4
Registered: April 2002

Junior Member

How to analyze a trace file generated(by TKprof)?and how do u analyze for tuning.Can anybody suggest me a documentation with examples?

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