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Message Posted: Tue, 25 Oct 2005 @ 17:52:38 GMT


     
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Subj:   Re: Help on Join Index with Outer Joins, please.
 
From:   Fred W Pluebell

A possible explanation: With OUTER JOINs, the join order matters. (OUTER JOIN is not associative.)

A Join Index defined for "A LEFT JOIN B" could possibly be used to satisfy queries against A alone (that's the idea in the manual excerpt you cited). But it can be used to satisfy queries with "more joins" only if the join order is compatible, e.g.

(A LEFT JOIN B) JOIN C should consider the JI

A LEFT JOIN (B JOIN C) should not



     
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