2019年8月OCP 071认证考试最新版本的考试原题-第30题

Posted 2020-11-22

choose two

Evalute these conmands which execate sucestully

CREATE SEQUENCE ord_seq

INCREMENT BY 1

START WITH 1

MAXVALUE 100000

CYCLE

CACHE 5000;

Which two statements are true atout the ORD_ITEMS table and the ORD_SEQ sequence?

A) Any user inserting rows into table ORD_ITEMS must have been granted access to sequence ORD_SEQ.

B) Colunn ORD_NO gets the next number from squence ORD_SEQ whenever a row is inserted into ORD_ITEMS and no explict value is given for ORD_NO.

C) Sepuence ORD_SEQ cycles back to 1 after every 5000 numbers and can cycle 20 times

D) IF sequence ORD_SEQ is dropped then the default value for column ORD_NO will be NULL for rows inserted into ORD_ITEMS.

E) Sequence ORD_SEQ is guaranteed not to genenate duplicate numbers.

Answer：AB

(解析：序列是可以共享的，但是需要给予 select 的权限;可以从序列中获取下一个值。)