Tom Lane wrote:
Ron Mayer <[EMAIL PROTECTED]> writes:
Couldn't the planner itself make a good guess if it should
keep trying based on the estimated cost?
if (the_best_plan_I_found_so_far_looks_like_itll_take_an_hour)
keep_optimizing_for_a_few_minutes
if (the_best_plan_I_found_so_far_looks_like_itll_take_0.01ms)
stop_planning_and_run_with_it
You're operating on a mistaken assumption, which is that we generate a
complete plan and then generate another. The places where we'd actually
be doing something with an effort variable are usually dealing with
small parts of plans, or even with preparatory calculations before we've
got anything plan-like at all. They haven't got a sufficiently holistic
view of what's happening to apply a rule like the above.
Then could the logic wait until the final plan is computed;
and if that final plan looks very expensive (compared with
the plan time so far), try again with the effort variable
automatically increased?
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