多项选择题
A.LOCK TABLE emp IN SHARE MODE;
B.LOCK TABLE emp IN EXCLUSIVE MODE;
C.DELETE FROM emp WHERE job=’MANAGER’;
D.INSERT INTO emp(empno,ename) VALUES (1289,’Dick’);
E.SELECT job FROM emp WHERE job=’CLERK’ FOR UPDATE OF empno;
多项选择题 WhichtwoarevalidlockinglevelsthatareusedbytransactionsinanOracledatabase?()
单项选择题 The ST_INFO master table has millions of rows that are updated very rarely. It has a STATE_CODE column that contains the value for 25 states. The table is frequently queried on the STATE_CODE column. Which type of index would you suggest to improve the query performance?()
多项选择题 AconstraintinatableisdefinedwiththeINITIALLYIMMEDIATEclause.YouexecutedtheALTERTABLEcommandwiththeENABLEVALIDATEoptiontoenabletheconstraintthatwasdisabled.Whatarethetwoeffectsofthiscommand?()