一个使用btree_gist代替btree的简单示例：

CREATE TABLE test (a int4);
-- create index
CREATE INDEX testidx ON test USING gist (a);
-- query
SELECT * FROM test WHERE a < 10;
-- nearest-neighbor search: find the ten entries closest to "42"
SELECT *, a <-> 42 AS dist FROM test ORDER BY a <-> 42 LIMIT 10;

使用排他约束来强制执行这样一条规则：动物园中的一个笼子只能容纳一种动物：

=> CREATE TABLE zoo (
  cage   INTEGER,
  animal TEXT,
  EXCLUDE USING gist (cage WITH =, animal WITH <>)
);

=> INSERT INTO zoo VALUES(123, 'zebra');
INSERT 0 1
=> INSERT INTO zoo VALUES(123, 'zebra');
INSERT 0 1
=> INSERT INTO zoo VALUES(123, 'lion');
ERROR:  conflicting key value violates exclusion constraint "zoo_cage_animal_excl"
DETAIL:  Key (cage, animal)=(123, lion) conflicts with existing key (cage, animal)=(123, zebra).
=> INSERT INTO zoo VALUES(124, 'lion');
INSERT 0 1

Teodor Sigaev（<teodor@stack.net>）、 Oleg Bartunov（<oleg@sai.msu.su>）和 Janko Richter（<jankorichter@yahoo.de>）。更多信息见 http://www.sai.msu.su/~megera/postgres/gist/。