Thread: BUG #16747: Unexpected behaviour of the overlaps function
The following bug has been logged on the website: Bug reference: 16747 Logged by: Paul Luchyn Email address: ddiamondbbackk@gmail.com PostgreSQL version: 11.8 Operating system: Windows Description: Hello! I'm working with the "overlaps" function. In my humble opinion it works incorrectly in one case. I have prepared some examples. 1) Two intervals with zero duration: SELECT (TIMESTAMP '2020-11-29 12:00:00.000', TIMESTAMP '2020-11-29 12:00:00.000') OVERLAPS (TIMESTAMP '2020-11-29 12:00:00.000', TIMESTAMP '2020-11-29 12:00:00.000'); ,the result is "true", looks fine. 2) Interval with zero duration, and non-zero interval: SELECT (TIMESTAMP '2020-11-29 12:00:00.000', TIMESTAMP '2020-11-29 12:00:00.000') OVERLAPS (TIMESTAMP '2020-11-29 12:00:00.000', TIMESTAMP '2020-11-29 12:02:00.000'); ,the result is "true", looks fine. 3) Two intervals with non-zero duration: SELECT (TIMESTAMP '2020-11-29 12:00:00.000', TIMESTAMP '2020-11-29 12:01:00.000') OVERLAPS (TIMESTAMP '2020-11-29 12:01:00.000', TIMESTAMP '2020-11-29 12:02:00.000'); , the result is false. The last case looks suspicious: logically these two intervals don't overlap, but they have common moment of time (2020-11-29 12:01:00.000). And one more question: is there any other function which will do the trick in the situation described in the last example?
On Thu, Nov 26, 2020 at 8:56 AM PG Bug reporting form <noreply@postgresql.org> wrote:
The following bug has been logged on the website:
Bug reference: 16747
Logged by: Paul Luchyn
Email address: ddiamondbbackk@gmail.com
PostgreSQL version: 11.8
Operating system: Windows
Description:
Hello!
I'm working with the "overlaps" function.
In my humble opinion it works incorrectly in one case.
Your examples perfectly match the documentation:
"Each time period is considered to represent the half-open interval start <= time < end, unless start and end are equal in which case it represents that single time instant. This means for instance that two time periods with only an endpoint in common do not overlap."
And one more question: is there any other function which will do the trick
in the situation described in the last example?
Create an explicit range out of the timestamps and use one of the range operators/functions?
David J.