Tag: databases

Which of the following is NOT a benefit of indexes?

Which of the following commands will rename a table?

Which command lets you put data into more than one table using a single command?

Examine the SQL statement that creates ORDERS table: CREATE TABLE orders (SER_NO NUMBER UNIQUE, ORDER_ID NUMBER, ORDER_DATE DATE NOT NULL, STATUS VARCHAR2(10) CHECK (status IN ('CREDIT', 'CASH')), PROD_ID NUMBER REFERENCES PRODUCTS(PRODUCT_ID), ORD_TOTAL NUMBER, PRIMARY KEY (order_id, order_date)); For which columns would an index be automatically created when you execute the above SQL statement?

Which three are DATETIME data types that can be used when specifying column definitions? (Choose three.)

Evaluate the SQL statement: TRUNCATE TABLE DEPT; Which three are true about the SQL statement? (Choose three.) A. It releases the storage space used by the table. B. It does not release the storage space used by the table. C. You can roll back the deletion of rows after the statement executes. D. You can NOT roll back the deletion of rows after the statement executes. E. An attempt to use DESCRIBE on the DEPT table after the TRUNCATE statement executes will display an error. F. You must be the owner of the table or have DELETE ANY TABLE system privileges to truncate the DEPT table.

Which two statements about sequences are true? (Choose two.) A. You use a NEXTVAL pseudo column to look at the next possible value that would be generated from a sequence, without actually retrieving the value. B. You use a CURRVAL pseudo column to look at the current value just generated from a sequence, without affecting the further values to be generated from the sequence. C. You use a NEXTVAL pseudo column to obtain the next possible value from a sequence by actually retrieving the value from the sequence. D. You use a CURRVAL pseudo column to generate a value from a sequence that would be used for a specified database column. E. If a sequence starting from a value 100 and incremented by 1 is used by more than one application, then all of these applications could have a value of 105 assigned to their column whose value is being generated by the sequence. F. You use a REUSE clause when creating a sequence to restart the sequence once it generates the maximum value defined for the sequence.

Which SQL statement generates the alias Annual Salary for the calculated column SALARY*12? A. SELECT ename, salary*12 'Annual Salary' FROM employees; B. SELECT ename, salary*12 "Annual Salary" FROM employees; C. SELECT ename, salary*12 AS Annual Salary FROM employees; D. SELECT ename, salary*12 AS INITCAP("ANNUAL SALARY") FROM employees

Which SQL statement accepts user input for the columns to be displayed, the table name, and the WHERE condition? A. SELECT &1, "&2" FROM &3 WHERE last_name = '&4'; B. SELECT &1, '&2' FROM &3 WHERE '&last_name = '&4''; C. SELECT &1, &2 FROM &3 WHERE last_name = '&4'; D. SELECT &1, '&2' FROM EMP WHERE last_name = '&4';

In which scenario would an index be most useful? A. The indexed column is declared as NOT NULL. B. The indexed columns are used in the FROM clause. C. The indexed columns are part of an expression. D. The indexed column contains a wide range of values.