OCP考试082

[orac1e@host01 ~] expdp system/oracle \
> FULL=Y \
> DUMPFILE=datadir1:full%U.dmp, datadir2:full%U.dmp \
> FILESIZE=2G \ > PARALLEL=4 \
> LOGFILE=datadir1:/expfull.1og \
> JOB_NAME=expfull
Which two statements are true about the expdp operation?

CREATE TABLE emp (emp_no NUMBER(2) CONSTRAINT emp_emp_no_pk PRIMARY KEY, ename VARCHAR2 (15) , salary NUMBER (8,2), mgr_no NUMBER(2)) ; 

ALTER TABLE emp ADD CONSTRAINT emp_mgr_fk FOREIGN KEY (mgr_no) REFERENCES emp (emp_no) ON DELETE SET NULL;

 ALTER TABLE Emp DISABLE CONSTRAINT emp_emp_no_pk CASCADE; 

ALTER TABLE emp ENABLE CONSTRAINT emp_emp_no_pk; 

Which two statements are true after execution?