range of composite types. I found this would be a great idea!!!
source code regress test ranges of composite types code part:
504 --
505 -- Ranges of composites
506 --
507
508 create type two_ints as (a int, b int);
509 create type two_ints_range as range (subtype = two_ints);
510
511 -- with force_parallel_mode on, this exercises tqueue.c's range remapping
512 select *, row_to_json(upper(t)) as u from
513 (values (two_ints_range(row(1,2), row(3,4))),
514 (two_ints_range(row(5,6), row(7,8)))) v(t);
-- composite type range.
create type mytype as (t1 int, t2 date);
-- create type my_interval as (t1 int, t2 interval);
select (2,'2022-01-02')::mytype ;
create type mytyperange as range(subtype = mytype);
I am thinking construct a composite type range that would be equivalent as:
select a, b::date from generate_series(1,8) a, generate_series('2022-01-01'::timestamp, '2022-01-31'::timestamp, interval '1 day') b;
for that means the following sql queries should return false:
select mytyperange (
(1,'2022-01-01')::mytype,
(8, '2022-01-31')::mytype, '[]') @> (2, '2020-01-19')::mytype;
select
(2, '2020-01-19')::mytype <@
mytyperange(
(1,'2022-01-01')::mytype,
(8, '2022-01-31')::mytype, '[]') ;
--does the range overlaps, that is, have any common element.
select
mytyperange ((2,'2020-12-30')::mytype,
(2, '2020-12-31')::mytype)
&&
mytyperange(
(1,'2022-01-01')::mytype,
(8, '2022-01-31')::mytype) ;
from the db fiddle link, so far I failed.
If this is possible then we may need a subtype_diff function and canonical function.
