Oracle OCP 19c 认证1Z0-082考试题库(第24题)-CUUG整理

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24、Evaluate these commands which execute successfully:

CREATE SEQUENCE ord_seq

INCREMENT BY 1

START WITH 1

MAXVALUE 100000

CYCLE

CACHE 5000;

CREATE TABLE ord_items(

ord_no NUMBER(4) DEFAULT ord_seq.NEXTVALUE NOT NULL,

item_no NUMBER(3),

qty NUMBER(3),

expiry_date DATE,

CONSTRAINT it_pk PRIMARY KEY(ord_no,item_no),

CONSTRAINIT ord_fk FOREIGN KEY(ord_no) REFERENCES orders (ord_no));

Which two statements are true about the ORD_ITEMS table and the ORD_SEQ sequence? (Choose two.)

A. If sequence ORD_SEQ is dropped then the default value for column ORD_NO will be NULL for rows inserted into ORD_ITEMS

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

C. Column ORD_NO gets the next number from sequence ORD_SEQ whenever a row is inserted into ORD_ITEMS and no explicit value is given for ORD_NO

D. Sequence ORD_SEQ cycles back to 1 after every 5000 numbers and can cycle 20 times

E. Sequence ORD_SEQ is guaranteed not to generate duplicate numbers