On 10/13/23 14:04, Dean Rasheed wrote: > 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. >
Right. > 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. > I do plan to backpatch this, yes. I don't think there are many people affected by this (few people are using infinite dates/timestamps, but maybe the overflow could be more common). regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
