Re: Between Node

On Thu, 2002-07-18 at 09:39, Tom Lane wrote:
> Rod Taylor <rbt@zort.ca> writes:
> > On Thu, 2002-07-18 at 00:56, Christopher Kings-Lynne wrote:
> >> I believe Tom mentioned that having BETWEEN as a node would allow him to do
> >> some sort of funky optimiser improvement.  Is that already done or does he
> >> still need to do it?
>
> > I don't know what improvement this would be.  I only touched the parser
> > and executor.
>
> In that case, this code is worse than before as far as developing plans
> goes.  The selectivity estimator needs to be taught about what BETWEEN
> means.  Currently it recognizes (x > foo AND x < bar) as a range query
> --- a BETWEEN node is obviously much easier to recognize, but you still
> have to add code to do it.
>
>             regards, tom lane
>