Re: constraint exclusion with a tsrange type

Ben Chobot <bench(at)silentmedia(dot)com> writes:
> Hey everybody, I'm having trouble getting constraint exclusion to work on a table partitioned with a tsrange type. I've distilled it down to this:
> create table t (
> id serial primary key,
> observed_window tsrange not null
> );
> create index t_window on t(observed_window);

> create table p1 (like t including all);
> alter table p1 add check ( tsrange('2018-1-1','2019-2-1') @> observed_window);
> alter table p1 inherit t;
> create table p2 (like t including all);
> alter table p2 inherit t;
> alter table p2 add check ( tsrange('2018-2-1','2019-3-1') @> observed_window);

> # explain select * from t where tsrange('2018-1-5','2018-1-6') @> observed_window;

Nope, sorry, there's no logic in there about ranges. You'd have to
break this down into something involving simple timestamp comparison
operators for constraint exclusion to be able to prove anything.

Might be a reasonable future extension, perhaps...

regards, tom lane