【单选题】有一个事务在session a被执行,begin;update tab_a set x = 1 where y = 3 ;update tab_a set x = 2 where y = 2 ;update tab_a set x = 3 where y = 3 ;commit;下面关于这个事务的描述正确的是:
【单选题】根据下列文章,请回答 41~45 题。 High Stress May Damage Memory A ccording to a report issued in May 1998,elderly people who have consistency high blood levels of cortisol(皮质醇)don’t score as well on memory tests as...
【单选题】有一个事务在session a被执行, begin; update tab_a set x = 1 where y = 3 ; update tab_a set x = 2 where y = 2 ; update tab_a set x = 3 where y = 3 ; commit; 下面关于这个事务的描述正确的是: