Join samll table with Big table

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krishstj
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Join samll table with Big table

Post by krishstj » Mon Jan 13, 2014 6:45 am

What happens when left table [ outer table ] is smaller when compared to right table [ inner table ] in joins.. [ outer and inner joins ]
will it affect the performance.

id10t
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Re: Join samll table with Big table

Post by id10t » Mon Jan 13, 2014 9:55 am

Hi!

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Last edited by id10t on Fri May 08, 2015 9:17 pm, edited 1 time in total.

NorbertKrupa
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Re: Join samll table with Big table

Post by NorbertKrupa » Thu Jan 16, 2014 10:04 pm

I don't believe that explicitly using a LIMIT improves the query performance (other than data transferred) as the optimizer must still perform the join on both tables. What I would suggest is to try to narrow your big table before the join;

Code: Select all

SELECT ...
FROM small_table
JOIN (SELECT ... FROM big_table WHERE some_column = 5 AND date > somedate) 
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