range type. For example:

<programlisting>

ALTER TABLE reservation ADD EXCLUDE USING gist (during WITH &amp;&amp;);

CREATE TABLE reservation (

during tsrange,

EXCLUDE USING gist (during WITH &amp;&amp;)

);

</programlisting>

That constraint will prevent any overlapping values from existing

in the table at the same time:

<programlisting>

INSERT INTO reservation VALUES

(1108,'[2010-01-01 11:30, 2010-01-0113:00)');

('[2010-01-01 11:30, 2010-01-0115:00)');

INSERT 0 1

INSERT INTO reservation VALUES

(1108,'[2010-01-01 14:45, 2010-01-01 15:45)');

('[2010-01-01 14:45, 2010-01-01 15:45)');

ERROR: conflicting key value violates exclusion constraint "reservation_during_excl"

DETAIL: Key (during)=([2010-01-01 14:45:00,2010-01-01 15:45:00)) conflicts

with existing key (during)=([2010-01-0114:30:00,2010-01-01 15:30:00)).

DETAIL: Key (during)=(["2010-01-01 14:45:00","2010-01-01 15:45:00")) conflicts

with existing key (during)=(["2010-01-0111:30:00","2010-01-01 15:00:00")).

</programlisting>

</para>

are equal:

<programlisting>

CREATE EXTENSION btree_gist;

CREATE TABLE room_reservation (

room text,

during tsrange,

INSERT INTO room_reservation VALUES

('123A', '[2010-01-01 14:30, 2010-01-01 15:30)');

ERROR: conflicting key value violates exclusion constraint "room_reservation_room_during_excl"

DETAIL: Key (room, during)=(123A, [2010-01-01 14:30:00,2010-01-01 15:30:00)) conflicts with

existing key (room, during)=(123A, [2010-01-01 14:00:00,2010-01-01 15:00:00)).

DETAIL: Key (room, during)=(123A, ["2010-01-01 14:30:00","2010-01-01 15:30:00")) conflicts

withexisting key (room, during)=(123A, ["2010-01-01 14:00:00","2010-01-01 15:00:00")).

INSERT INTO room_reservation VALUES

('123B', '[2010-01-01 14:30, 2010-01-01 15:30)');