Re: Partitioning by month causing an error?

This is really interesting to me: why? Running select '2019-04-30'::date
between '2019-04-01'::date and '2019-04-30'::date; yields true, and
generally the lower and upper bounds are inclusive in any kind of between
check for languages I am familiar with.

Appreciate the answer, just curious. Thanks as always Tom.

On Fri, Dec 20, 2019 at 6:59 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Wells Oliver <wells(dot)oliver(at)gmail(dot)com> writes:
> > I have a partition per each month, like this:
> > CREATE TABLE mmd_yr2019_3 PARTITION OF mmd FOR VALUES FROM ('2019-03-01')
> > TO ('2019-03-31');
> > CREATE TABLE mmd_yr2019_4 PARTITION OF mmd FOR VALUES FROM ('2019-04-01')
> > TO ('2019-04-30');
>
> > This breaks for dates at the end of the month. What's the better way to
> > write the bounds? 3/1 to 4/1 and then 4/1 to 5/1? Does that cause some
> > overlap issue?
>
> The rule is that a range partition from A to B covers values A <= X < B.
> So you should be using first-of-the-month dates for all of these
> values. As you have it, there's gaps in the allowable values,
> totally aside from the PITA factor of having to identify the last
> day of each month accurately.
>
> regards, tom lane
>

--
Wells Oliver
wells(dot)oliver(at)gmail(dot)com <wellsoliver(at)gmail(dot)com>