"Marinos J. Yannikos" <[EMAIL PROTECTED]> writes:
> it seems to me that the optimizer parameters (like random_page_cost 
> etc.) could easily be calculated and adjusted dynamically be the DB 
> backend based on the planner's cost estimates and actual run times for 
> different queries. Perhaps the developers could comment on that?

No, they are not that easy to determine.  In particular I think the idea
of automatically feeding back error measurements is hopeless, because
you cannot tell which parameters are wrong.

> I'm not sure how the parameters are used internally (apart from whatever 
> "EXPLAIN" shows), but if cpu_operator_cost is the same for all 
> operators, this should probably also be adjusted for individual 
> operators (I suppose that ">" is not as costly as "~*").

In theory perhaps, but in practice this is far down in the noise in most

                        regards, tom lane

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