Tom Lane wrote:
Alban Hertroys <alban@xxxxxxxxxxxxxxxxx> writes:
With what I have in mind, both overlap and equality would violate the
unique constraint. I don't quite see why someone'd want to forbid
overlap but to allow equality; isn't not allowing equality the whole
point of a unique constraint?
You're missing the point. Letting "~" represent the operator that
tests for interval-overlap, we can have
A --------------
B ------------------
I'd say "unique constraint violation" right here (provided there's a
unique constraint on this column, of course). The order in which these
are inserted/updated doesn't seem to matter either. I'm afraid I'm still
missing the point... or maybe I'm not wrong???
C ----------------
so that A ~ B and B ~ C but not A ~ C. This is too much unlike normal
equality for a btree to work with "~" as the "equality" operator.
--
Alban Hertroys
alban@xxxxxxxxxxxxxxxxx
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