Re: Planner creating ineffective plans on LEFT OUTER joins

Simon Riggs <simon@2ndquadrant.com> writes:
> On Thu, 2008-06-26 at 12:36 -0400, Robert Haas wrote:
>> It's my understanding that the philosophy of the PGDG in the past has
>> been to avoid putting any kind of hints into the system, focusing
>> rather an improving the planning of queries.

> It's not a specific hint, its a general goal setting.

Right.  There are definitely places where we've made engineering
judgements to not attempt a particular type of optimization because it'd
be too expensive compared to the typical payoff.  Simon's idea has some
merit for providing a framework to deal with that type of situation.
However, just adding a GUC variable isn't going to make anything happen
--- we'd need some concrete plans about what we'd do with it.
        regards, tom lane