On Thu, 21 Dec 2023 at 09:26, Amit Kapila <amit.kapil...@gmail.com> wrote:
> A conflicting column where NULL indicates no conflict, and other > > values indicate the reason for the conflict, doesn't seem too bad. > > > > This is fine too. > I prefer this option. There is precedent for doing it this way, for example in pg_stat_activity.wait_event_type. The most common test of this field is likely to be "is there a conflict" and it's better to write this as "[fieldname] IS NOT NULL" than to introduce a magic constant. Also, it makes clear to future maintainers that this field has one purpose: saying what type of conflict there is, if any. If we find ourselves wanting to record a new non-conflict status (no idea what that could be: "almost conflict"? "probably conflict soon"?) there would be less temptation to break existing tests for "is there a conflict".
