Chapter 10 Quiz

It is always possible to update the underlying table(s) through every view, whether it be a simple view or a complex view. True False

FALSE

Which of the following are characteristics of a complex view. Select all that apply. Subqueries Group functions JOINS Conversion functions

Subqueries Group functions JOINS

For which of the following, will Oracle automatically create an index? primary key column column defined as UNIQUE column defined as NOT NULL a foreign key column

primary key column column defined as UNIQUE

How many tables can be part of a simple view? 2 1 as many as you like not enough information is given to answer

1

What is true of the following code to make a new view? 01 SELECT OR REPLACE employee_view_phone AS 02 SELECT employee_id, last_name, phone_number 03 FROM employees; there is an error on line 01 because the keyword SELECT should be CREATE It will run and make a new view called employee_view_phone there is an error on line 02 because the columns do not have aliases there is an error after line 03 because there is no ORDER BY

there is an error on line 01 because the keyword SELECT should be CREATE

What is true of the following code to make a new view? 01 CREATE OR REPLACE VIEW employee_vue_phone AS 02 SELECT employee_id, first_name || ' ' || last_name, phone_number 03 FROM employees; It will run and make a new view called employee_vue_phone there is an error on line 01 because OR REPLACE is missing there is an error on line 02 because the 2nd column must have an alias there is an error because there is no ORDER BY

there is an error on line 02 because the 2nd column must have an alias

Which of the following is(are) database object(s)? view sequence Create statement index

view sequence index

Which of the following statements will define a new index on the Op_key column of the CodeOps table? CREATE CodeOps.Op_Key.idx (Op_Key) References CodeOps; CREATE CodeOps_Op_key_idx ON CodeOps.Op_key; CREATE INDEX CodeOps_Op_key_idx REFERENCES CodeOps.Op_Key; CREATE INDEX CodeOps_Op_key_idx ON CodeOps(Op_Key);

CREATE INDEX CodeOps_Op_key_idx ON CodeOps(Op_Key);

One place to get a master list of all of the views that form the data dictionary is: DICTIONARY DATA_DICTIONARY USER_DICTIONARY USER_CATALOG

DICTIONARY

Which of these is a characteristic of a complex view, rather than a simple view? (Choose all that apply.) MAX, MIN, SUM, or COUNT in the SELECT clause A subquery within the SELECT statement A selection of rows with a WHERE clause Join of two or more tables

MAX, MIN, SUM, or COUNT in the SELECT clause A subquery within the SELECT statement Join of two or more tables

How do you retrieve data from a view named OrderlineView? SELECT * FROM OrderlineView; bad idea- the idea behind a view is to keep the data from being viewed it is not possible CREATE VIEW statement will display the data

SELECT * FROM OrderlineView;

All database data is stored in: TABLES TABLES and VIEWS TABLES, VIEWS, and INDEXES None of the above

TABLES

A view is a SELECT statement that is stored in the database and has a name, and is accessible as though it were a table. True False

TRUE

One advantage of using views is that different views of the same data can be presented to different users. True False

TRUE

Which of the following statements are true concerning Oracle indexes. Select all that apply. You need to explicitly create the Primary Key index The purpose of an index on a column is to speed up a query that uses that column An index is stored in a file separate from the table it indexes The user must routinely perform maintenance on a table's indexes to keep them running at top performance.

The purpose of an index on a column is to speed up a query that uses that column An index is stored in a file separate from the table it indexes

Which of the following are legitimate reasons for using views in a database application? (Choose all that are legitimate.) To give the DBA something to do. To provide an additional level of security. To simplify complex queries. To prevent access to sensitive data by some users.

To provide an additional level of security. To simplify complex queries. To prevent access to sensitive data by some users.

The term meta-data means distributed data global data that is accessible throughout the database data about data data that is automatically updated and maintained

data about data

A sequence is part of a table used exclusively to create primary key values is the only way to create primary key values none of the above

none of the above

Which of the following will not cause the contents of the data dictionary to be changed in some way? create a new table modify the data type of an existing column add a new sequence none of the above

none of the above