Performance on JOIN - SQL Server Forums

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Performance on JOIN

Author

Topic

sql_server_dba
Posting Yak Master

167 Posts

Posted - 2012-04-19 : 13:00:42

If we have 3 tables A, B and C with A having 1 million, B having 2 million and C having only 100000.

What would be the difference between joining
SELECT *
FROM A
INNER JOIN B
ON A.x = B.X
INNER JOIN C
ON A.X = C.X

and

SELECT *
FROM A
INNER JOIN C
ON A.x = C.x
INNER JOI B
ON A.x = B.x

Will there be any performance difference?????

sunitabeck
Master Smack Fu Yak Hacker

5155 Posts

Posted - 2012-04-19 : 14:32:30

There would not be any performance difference.

What you could do though, is to make sure that:
a) there are appropriate indexes on the join columns, and limit the rows retrieved via where clauses if applicable
b) you list only the columns you need in the select list instead of using SELECT *

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