Robert Haas wrote: > On Sat, Sep 5, 2009 at 8:19 PM, Karl Denninger<k...@denninger.net> wrote: > >> There was a previous thread and I referenced it. I don't have the other one >> in my email system any more to follow up to it. >> >> I give up; the attack-dog crowd has successfully driven me off. Ciao. >> > > Perhaps I'm biased by knowing some of the people involved, but I don't > think anyone on this thread has been anything but polite. It would > certainly be great if PostgreSQL could properly estimate the > selectivity of expressions like this without resorting to nasty hacks, > but it can't, and unfortunately, there's really no possibility of that > changing any time soon. Even if someone implements a fix today, the > soonest it will appear in a production release is June 2010. So, any > suggestion for improvement is going to be in the form of suggesting > that you modify the schema in some way. I know that's not really what > you're looking for, but unfortunately it's the best we can do. > > As far as I can tell, it is not correct to say that you referenced the > previous thread. I do not see any such reference. > > ...Robert > > I was asking about modifying the schema.
The current schema is an integer being used as a bitmask. If the planner knows how to handle a type of "bit(X)" (and will at least FILTER rather than NESTED LOOP it on a select, as happens for an Integer used in this fashion), that change is easier than splitting it into individual boolean fields. -- Karl
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