Alban Hertroys <alban@xxxxxxxxxxxxxxxxx> writes:
> They're adjacent, they don't overlap. Check the documentation on
> OVERLAPS, I'm sure it's explicit about whether it is inclusive or
> exclusive (the latter apparently).
It's not very clear, but the spec defines (S1,T1) OVERLAPS (S2,T2)
as
( S1 > S2 AND NOT ( S1 >= T2 AND T1 >= T2 ) )
OR
( S2 > S1 AND NOT ( S2 >= T1 AND T2 >= T1 ) )
OR
( S1 = S2 AND ( T1 <> T2 OR T1 = T2 ) )
(for the simple case where there are no nulls and S1 <= T1, S2 <= T2).
So it looks to me like the intervals are actually considered to be
half-open intervals [S1, T1). Which is something that has its uses,
but it's a bit surprising compared to, say, BETWEEN.
If you don't like it, write your own comparison function ...
regards, tom lane
