Re: Statistics and selectivity estimation for ranges

Alexander Korotkov <aekorotkov@gmail.com> writes:
> Ok, we've to decide if we need "standard" histogram. In some cases it can
> be used for more accurate estimation of < and > operators.
> But I think it is not so important. So, we can replace "standard" histogram
> with histograms of lower and upper bounds?

You should assign a new pg_statistic "kind" value (see pg_statistic.h)
rather than mislabel this as being a standard histogram.  However,
there's nothing wrong with a data-type-specific stats collection
function choosing to gather only this type of histogram and not the
standard one.

			regards, tom lane