Supporting range types

One of the most powerful features of PostgreSQL is the ability to make use of range types. Why is that important? When dealing with all kinds of data, we will often see that information is only valid for a certain period. Maybe we want to store prices that change over time, or we want to handle measurement data that is only valid for a certain period.

Normally, what you would do is use two columns, as shown in the next example:

test=# CREATE TABLE t_price (
    id       serial,
    product_name   text,
    price     numeric,
    price_from   date,
    price_until   date,
    CHECK (price_until >= price_from)
);
CREATE TABLE

In this case, the price is valid for a certain period. If we want to query whether price periods overlap...