Обсуждение: [HACKERS] Turn off transitive joins

Hi all,

Is there some way by which I can tell postgresql to not to consider transitive joins while considering join pairs.

I.e. Let's say a query has two join predicates one between A & B relations and the other between B and C relations.

While constructing the DP to find the best join order, the Optimizer also consider join between A & C, which can be thought of as a transitive join.

Is their some way to turn this off or tell postgresql to not to consider these type of joins ?

Gourav Kumar <gourav1905@gmail.com> writes:
> Is there some way by which I can tell postgresql to not to consider
> transitive joins while considering join pairs.

No ... and you have presented no reason whatever why we should consider
adding such a capability.

Maybe you should be trying to construct your join graph someplace
earlier, before the optimizer processes the join quals.
        regards, tom lane


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I don't think there is any need to add any such capability in postgresql, but I need it for my work.

I need the join qualifiers.