Date: Mon, 29 Apr 2019 21:22:16 +0300
From: Eugen Konkov <kes-kes@yandex.ru>
Message-ID: <1265663903.20190429212216@yandex.ru>
To: pgsql-docs@lists.postgresql.org
Subject: Re: Why 'infinity' is not in range '[2019-01-02, infinity]'?
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  <5f6b986b-de4d-8a43-1366-fc8c3aed6319@postgresql.org>
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1.
Also I found next ambiguous part:

    select upper_inf(  '["2018-08-14","Infinity")'::daterange );


Thanks  jstag  from  IRC for explanation that unbound and infinite are
different essence.

Thus, on the page
https://www.postgresql.org/docs/11/functions-range.html

lower_inf(anyrange)     boolean         is the lower bound infinite?    low=
er_inf('(,)'::daterange)     true
upper_inf(anyrange)     boolean         is the upper bound infinite?    upp=
er_inf('(,)'::daterange)     true


should be spelled:

lower_inf(anyrange)     boolean         is the lower bound unbound?    lowe=
r_inf('(,)'::daterange)     true
upper_inf(anyrange)     boolean         is the upper bound unbound?    uppe=
r_inf('(,)'::daterange)     true

should not?


2.
I  do  not  know, it where are any sense to distinguish:
[ 2019-01-01, infinity ) and [ 2019-01-01, )

and because: https://www.postgresql.org/docs/11/rangetypes.html#RANGETYPES-=
INFINITE

 This is equivalent to considering that the lower bound is =E2=80=9Cminus i=
nfinity=E2=80=9D, or the upper bound is =E2=80=9Cplus infinity=E2=80=9D, re=
spectively

and because of next statement does not work:

 select '[2019-01-02,"infinity"]'::daterange @> 'infinity'::date;


if   you  allow I will suggest to map/convert 'infinity' value to
unbound range, for datatypes which defines 'infinity' value.
so these two become same:

    [ 2019-01-01, infinity ) and [ 2019-01-01, )

It seems more consistent in compare to current behavior.