Postgres date overlapping constraint

Ok i ended up doing this :

CREATE TABLE test (
    from_ts TIMESTAMPTZ,
    to_ts TIMESTAMPTZ,
    account_id INTEGER DEFAULT 1,
    product_id INTEGER DEFAULT 1,
    CHECK ( from_ts < to_ts ),
    CONSTRAINT overlapping_times EXCLUDE USING GIST (
        account_id WITH =,
        product_id WITH =,
        period(from_ts, CASE WHEN to_ts IS NULL THEN 'infinity' ELSE to_ts END) WITH &&
    )
);

Works perfectly with infinity, transaction proof.

I just had to install temporal extension which is going to be native in postgres 9.2 and btree_gist available as an extension in 9.1 CREATE EXTENSION btree_gist;

nb : if you don’t have null timestamp there is no need to use the temporal extension you could go with the box method as specified in my question.