gistfile1.txt

Connection A:

test=> begin;
BEGIN
test=> update test set foo = 2 where id = 1;
UPDATE 1
test=> end;
COMMIT

Connection B:

test=> begin transaction isolation level repeatable read;
BEGIN
test=> update test set foo = 3 where id = 1;
錯誤:  因為並行更新，無法序列化存取
test=> end;
ROLLBACK