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Database Programming

Database Programming. Sections 13. 13.1.4. 1. Which statements are True about the following sequence? The sequence was used to generate numbers for the DJ on Demand D_CDS table cd_numbers column.

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Database Programming

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  1. Database Programming Sections 13

  2. 13.1.4 • 1. Which statements are True about the following sequence? The sequence was used to generate numbers for the DJ on Demand D_CDS table cd_numbers column. • CREATE SEQUENCE cd_numbers_sqINCREMENT BY 15START WITH 105MAXVALUE 999NOMINVALUECYCLENOCACHE • ____a. The value 165 will not be generated by this sequence. • ____b. The value 999 will not be generated by this sequence. • ____c. This sequence would be appropriate for PRIMARY KEY values. • ____d. If the D_CDS table is deleted, the sequence is also deleted. • ____e. If the systems fails sequence values will be lost. • ____f. USER_OBJECTS documents this sequence in the data dictionary. • ____g. The START WITH value could be changed with an ALTER SEQUENCE. Marge Hohly

  3. 13.1.5 • 2. In the CREATE TABLE statement shown below, circle the letter of the line(s) that will automatically create an index. • a. CREATE TABLE employees( • b. employee_id NUMBER(6), • c. last_name VARCHAR2(25) NOT NULL, • d. email VARCHAR2(25) CONSTRAINT emp_email_ukUNIQUE, • e. salary NUMBER(8,2), • f. commission_pct NUMBER(2,2), • g. hire_date DATE NOT NULL, • h. CONSTRAINT employee_id_pk PRIMARY KEY(employee_id), • i. CONSTRAINT emp_dept_fk FOREIGN KEY(department_id)REFERENCES • j. departments(department_id) Marge Hohly

  4. 13.1.6 • 3. What data dictionary view contains the sequences created by a schema? • a. SEQUENCE_VIEW • b. USER_SEQUENCES • c. SEQUENCE_NAMES • d. USER_VIEWS • 4. What is the proper syntax for changing the emp_email_index on the email column of the employees table? • a. CREATE INDEX emp_email_index ON employees (email); • b. ALTER INDEX emp_mail_index FROM employees(email); • c. CREATE AND REPLACE INDEX emp_email_index ON employees, COLUMN = email; • d. ADD INDEX emp_email_index INTO employees (email); • e. None of the above • Indexes cannot be modified -- instead, DROP and re-create. Marge Hohly

  5. 13.1.7 • 5. Which data dictionary view is used to view the table name, the index name, and the column name that the index is based on? • a. USER_TABLE_INDEXES • b. USER_COLUMNS • c. USER_IND_COLUMNS • d. ALL_INDEXES • 6. If the PUBLIC option is not included in the CREATE SYNONYM syntax, which of the following is True? • a. Users cannot lengthen object names. • b. The DBA does not have access to the synonym. • c. The synonym is not accessible to all users. • d. All object names must be qualified with PUBLIC. Marge Hohly

  6. 13.1.8 • 7. What are the last three numbers created by the sequence? • CREATE SEQUENCE sample_seqINCREMENT BY 3START WITH 6MAXVALUE 14NOMINVALUECYCLENOCACHE • a. 3, 6, 9 • b. 6, 9, 12 • c. 9, 12, 15 • d. 9, 12, 14 • 8. Which of the following is a good reason to create an index? • a. A column has a large number of null values. • b. A column has a narrow range of values. • c. Most queries are expected to return more than 5% of the rows. • d. A table is updated frequently.. Marge Hohly

  7. 13.1.9 • 9. Which of the following constraints can be created at the table level? • a. NOT NULL • b. FOREIGN KEY • c. PRIMARY KEY • d. UNIQUE COMPOSITE KEY • 10. Which of the following cannot contain a single-row function? • a. SELECT • b. FROM • c. WHERE • d. ORDER BY Marge Hohly

  8. 13.4.4 • 1. The CREATE TABLE AS SELECT syntax can be used to: (choose all that apply) • a. create a new table without data based on the structure and column names of an existing table. • b. create a new table containing the same structure but different column names as an existing table. • c. create a new table containing the structure and data of an existing table. • d. create a set of pseudocolumns that query and display part of an existing table. • 2. Which identifiers listed below are invalid names for use in the Oracle database? • a. a table named: Long_table_name_for_storing_data • b. a sequence named: 4generatingUniqueNumbers • c. a column named: Primary_Key$Column • d. a view named: My&ViewOfData Marge Hohly

  9. Guidelines to grant object privileges • To grant privileges on an object, the object must be in your own schema, or you must have been granted the object privileges WITH GRANT OPTION. • An object owner can grant any object privilege on the object to any other user or role of the database. • The owner of an object automatically acquires all object privileges on that object. Marge Hohly

  10. Syntax Marge Hohly

  11. 13.4.5 • 3. SYSDATE and USER are not permitted as references in: • a. the values clause of an INSERT statement • b. default values for column definitions • c. check constraints • d. none of the above • 4. What will be the column names resulting from the following view definition: CREATE OR REPLACE VIEW Name_Vu (Person_Name, Title, Pay)AS SELECT last_name AS name, job_id position, salary AS compensation FROM employees; • a. LAST_NAME, JOB_ID, POSITION • b. PERSON_NAME, TITLE, PAY • c. NAME, POSITION, COMPENSATION • d. none of the above Marge Hohly

  12. 13.4.6 • 5. To ensure that DML operations performed on a view stay within the domain of the view, use which of the following? • a. AS CHECK • b. CASCADE • c. WITH CHECK OPTION • d. CHECK CONSTRAINT • 6. A column that will be used to store text data with a size of 4,000 bytes or larger should be defined as which data type? • a. varchar2 • b. CLOB • c. LONG • d. CHAR • 7. To store time with fractions of seconds, which data type should be used for the column? • a. date • b. datetime • c. timestamp • d. interval day to second Marge Hohly

  13. 13.4.7 • 8. The data type TIMESTAMP WITH TIME ZONE stores: • a. The current date, time (including fractions of seconds), and time zone • b. The current date, time (without fractions of seconds), and time zone • c. The current date, time (including fractions of seconds), and offset from UTC • d. The current date, time (including fractions of seconds), and offset from the database time • 9. To keep a table from being accessed so it can be dropped when the demand on system resources is lower, use: • a. ALTER TABLE modify column • b. ALTER TABLE drop column • c. ALTER TABLE set unused • d. DROP “columnname”FROM songs; Marge Hohly

  14. 13.4.8 • 10. Comments on tables and columns can be stored for documentation by: • a. embedding /* comment */ within the definition of the table. • b. using the ALTER TABLE CREATE COMMENT syntax • c. using the COMMENT ON TABLE or COMMENT ON COLUMN • d. using an UPDATE statement on the USER_COMMENTS table • 11. To allow the delete of a parent (primary key) record that has referenced foreign key values, use • a. ON DELETE RESTRICT • b. ON DELETE SET NULL • c. ON DELETE CASCADE • d. ON DELETE DELETE Marge Hohly

  15. 13.4.9 • 12. (True/False) Multicolumn constraints can be defined at the column or table level. • 13. (True/False) To give a constraint a name other than SYS_n, precede it with the keyword “CONSTRAINT.” • 14. (True/False) NOT NULL constraints are created implicitly when you create a new table using subquery CREATE TABLE AS syntax. Marge Hohly

  16. 13.4.10 • 15. By default, unique indexes are created when which constraints are enabled? • a. PRIMARY KEY • b. FOREIGN KEY • c. NOT NULL • d. CHECK • e. UNIQUE • 16. Constraints can be: (choose all that apply) • a. enabled or disabled • b. created or dropped • c. changed through “alter constraint” • d. viewed in user_constraints • 17. (True/False) Like tables, to change a view definition, use the ALTER VIEW syntax. • 18. (True/False) To use a view, a person must have security privileges on the tables that the view contains. • 19. (True/False) INSERT, UPDATE, and DELETE are never permitted on a view created with the WITH CHECK OPTION clause. Marge Hohly

  17. 13.4.11 • 20. An inline view is created by placing a subquery in the FROM clause and: • a. updating the user_views data dictionary view • b. using a GROUP BY clause to group the columns • c. enclosing in parentheses the SELECT clause • d. giving the subquery an alias • 21. Top-n-analysis makes use of a sorted inline view in the FROM clause and (in the outer query): • a. a rowid pseudocolumn in the WHERE clause • b. the level pseudocolumn in the WHERE clause • c. a rownum column in the ORDER BY clause • d. ROWNUM in the WHERE clause • 22. If you wanted to see the value that you fetched from a sequence named “my_SEQ,” you should reference: • a. my_SEQ.last_value • b. my_SEQ.nextval • c. my_SEQ.currval • d. my_SEQ.maxval. Marge Hohly

  18. 13.4.12 • 23. Sequences can be used to: (choose all that apply) • a. ensure that primary key values will be unique and consecutive • b. ensure that numbers will be unique even though gaps may exist • c. use a range of numbers and optionally cycle through them again • d. set a fixed interval for successive numbers • 24. The ALTER SEQUENCE syntax can be used to: (choose all that apply) • a. change the START WITH of an existing sequence • b. reset the MAX VALUE to a lower number than was last used • c. change the name of the sequence • d. change the interval of the sequence • 25. (True/False) Indexes always speed up access to rows in a table. • 26. (True/False) To use an index, you must name it in the FROM clause of your query. Marge Hohly

  19. 13.4.12 • 27. A function-based (or functional) index stores sorted information that contains: • a. a rowid and the column(s) key value(s) • b. a rowid and a function return based on the column key value • c. a rowid and a method that dynamically acts on the key value • d. a bitmap for a range of rowids that correspond to a key value • 28. A shareable alias for a database object is called a: • a. pseudonym • b. rowid • c. synonym • d. view • 29. To prevent others from performing DML operations on tables you share in your schema: • a. GRANT select • b. GRANT view only • c. GRANT unused • d. GRANT revoke • 30. (True/False) The owner of an object automatically acquires all object privileges on objects in his/her schema. Marge Hohly

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