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JOIN and table size

 
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revdpoel

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Joined: 01 Nov 2006
Posts: 56

PostPosted: Sun Feb 08, 2009 1:58 am    Post subject: JOIN and table size
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Suppose I have a small table with 1000 rows (A) and a big table with 2 million rows (B).
When I am doing an INNER, LEFT OUTER or FULL JOIN does it make any difference where the small and big table are positioned?

So as an example
A left join B does that have the same performance as
B left join A??
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dick scherrer

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Joined: 23 Nov 2006
Posts: 19270
Location: Inside the Matrix

PostPosted: Sun Feb 08, 2009 4:18 am    Post subject:
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Hello,

Not really - as long as the query and the tables are well defined for performance.

If your query generates a catesian product, it will not matter which table is mentioned first - it will run poorly regardless. . .
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