Re: Planner question - "bit" data types

Robert Haas wrote:
> On Sat, Sep 5, 2009 at 8:19 PM, Karl Denninger<karl(at)denninger(dot)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