On Fri, 13 Oct 2023 at 11:44, Tomas Vondra <tomas.von...@enterprisedb.com> wrote: > > On 10/13/23 11:21, Dean Rasheed wrote: > > > > Is this only inefficient? Or can it also lead to wrong query results? > > I don't think it can produce incorrect results. It only affects which > values we "merge" into an interval when building the summaries. >
Ah, I get it now. These "distance" support functions are only used to see how far apart 2 ranges are, for the purposes of the algorithm that merges the 2 closest ranges. So if it gets it wrong, it only leads to a poor choice of ranges to merge, making the query inefficient, but still correct. Presumably, that also makes this kind of change safe to back-patch (not sure if you were planning to do that?), since it will only affect range merging choices when inserting new values into existing indexes. Regards, Dean
