更多"Evaluate these two SQL statements: "的相关试题:
[单项选择]Evaluate these two SQL statements:SELECT last_name, salary, hire_dateFROM EMPLOYEES ORDRE BY salary DESC; SELECT last_name, salary, hire_dateFROM EMPOLYEES ORDER BY 2 DESC; What is true about them?（）
A. The two statements produce identical results.
B. The second statement returns a syntax error.
C. There is no need to specify DESC because the results are sorted in descending order by default.
D. The two statements can be made to produce identical results by adding a column alias for the salary column in the second SQL statement.
[单项选择] Evaluate these two SQL statements: SELECT last_name, salary , hire_date FROM EMPLOYEES ORDER BY salary DESC; SELECT last_name, salary, hire_date FROM EMPLOYEES ORDER BY 2 DESC; What is true about them?（）
A. The two statements produce identical results.
B. The second statement returns a syntax error.
C. There is no need to specify DESC because the results are sorted in descending order by default.
D. The two statements can be made to produce identical results by adding a column alias for the salary column in the second SQL statement.
[单项选择] Evaluate the set of SQL statements: CREATE TABLE dept (deptno NUMBER(2), dname VARCHAR2(14), loc VARCHAR2(13)); ROLLBACK; DESCRIBE DEPT What is true about the set?（）
A. The DESCRIBE DEPT statement displays the structure of the DEPT table.
B. The ROLLBACK statement frees the storage space occupied by the DEPT table.
C. The DESCRIBE DEPT statement returns an error ORA-04043: object DEPT does not exist.
D. The DESCRIBE DEPT statement displays the structure of the DEPT table only if there is a COMMIT statement introduced before the ROLLBACK statement.
[多项选择]Which two statements about the SQL Management Base (SMB) are true? （）(Choose two.)
A. It contains only SQL profiles generated by SQL Tuning Advisor.
B. It stores plans generated by the optimizer using a stored outline.
C. It is part of the data dictionary and stored in the SYSAUX tablespace.
D. It is part of the data dictionary and stored in the SYSTEM tablespace.
E. It contains the statement log, the plan history, plan baselines, and SQL profiles.
[多项选择]Which two statements regarding a SQL profile are true?（）
A. It is built by Automatic Tuning Optimizer.
B. It cannot be stored persistently in the data dictionary.
C. It can be used by the query optimizer automatically.
D. It can be created manually by using the CREATE PROFILE command.
[多项选择]Which three statements are true about SQL plan directives?（）
A. They are tied to a specific statement or SQL id.
B. They instruct the maintenance job to collect missing statistics or perform dynamic sampling to generate a more optimal plan.
C. They are used to gather only missing statistics.
D. They are created for a query expression where statistics are missing or the cardinality estimates by the optimizer are incorrect.
E. They instruct the optimizer to create only column group statistics.
F. Improve plan accuracy by persisting both compilation and execution statistics in the SYSAUX tablespace.
[多项选择]Which two statements are true regarding the SQL Repair Advisor?（）
A. The SQL Repair Advisor can be invoked to tune the performance of the regressed SQL statements.
B. The SQL Repair Advisor can be invoked even when the incident is not active for a SQL statement crash.
C. The SQL Repair Advisor is invoked by the Health Monitor when it encounters the problematic SQL statement.
D. The DBA can invoke the SQL Repair Advisor when he or she receives an alert generated when a SQL statement crashes and an incident is created in the ADR.
[单项选择] Evaluate this SQL statement: SELECT ename, sal, 12*sal+100 FROM emp; The SAL column stores the monthly salary of the employee. Which change must be made to the above syntax to calculate the annual compensation as "monthly salary plus a monthly bonus of $100, multiplied by 12"?（）
A. No change is required to achieve the desired results.
B. SELECT ename, sal, 12*(sal+100) FROM emp;
C. SELECT ename, sal, (12*sal)+100 FROM emp;
D. SELECT ename, sal+100,*12 FROM emp;
[单项选择] Evaluate the SQL statement: SELECT ROUND(TRUNC(MOD(1600,10),-1),2) FROM dual; What will be displayed? （）
A. 0
B. 1
C. 0.00
D. An error statement
