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asdf Quiz on Chapter 3 (True/False), created by . . on 31/08/2016.

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Chapter 3 (True/False)

Question 1 of 30

1

1) The practical significance of taking the logical view of a database is that is serves as reminder of the simple file concept of data storage.

Select one of the following:

  • True
  • False

Explanation

Question 2 of 30

1

2) You can think of a table as a persistent representation of a logical relation.

Select one of the following:

  • True
  • False

Explanation

Question 3 of 30

1

3) Because the relational model uses attribute values to establish relationships among tables, many data-base susers correctly assume that the term relation refers to such relationships.

Select one of the following:

  • True
  • False

Explanation

Question 4 of 30

1

4) The order of the rows and columns is important to the DBMS.

Select one of the following:

  • True
  • False

Explanation

Question 5 of 30

1

5) Numeric data are data on which you can perform meaningful arithmetic procedures.

Select one of the following:

  • True
  • False

Explanation

Question 6 of 30

1

6) Character data can contain any character or symbol intended for mathematical manipulation.

Select one of the following:

  • True
  • False

Explanation

Question 7 of 30

1

7) Each table in a relational database must have a primary key.

Select one of the following:

  • True
  • False

Explanation

Question 8 of 30

1

8) The idea of determination is unique to the database environment.

Select one of the following:

  • True
  • False

Explanation

Question 9 of 30

1

9) In a relational model, if A determines B, C, and D, you write A = B, C, D.

Select one of the following:

  • True
  • False

Explanation

Question 10 of 30

1

10) Only a single attribute, not multiple attributes, can define functional dependence.

Select one of the following:

  • True
  • False

Explanation

Question 11 of 30

1

11) If the attribute (B) is functionally dependent on a composite key (A) but not on any subset of that composite key, the attribute (B) is fully functionally dependent on (A).

Select one of the following:

  • True
  • False

Explanation

Question 12 of 30

1

12) A null is created when you press the Enter key or the Tab key to move to the next entry without making a prior entry of any kind.

Select one of the following:

  • True
  • False

Explanation

Question 13 of 30

1

13) There is never a good reason to use null values in a database.

Select one of the following:

  • True
  • False

Explanation

Question 14 of 30

1

14) Depending on the sophistication of the application development software, nulls can create problems when functions such as COUNT, AVERAGE, and SUM are used.

Select one of the following:

  • True
  • False

Explanation

Question 15 of 30

1

15) Tables within a database share common attributes that enable the tables to be linked together.

Select one of the following:

  • True
  • False

Explanation

Question 16 of 30

1

16) A foreign key must exist in both tables that have a relationship

Select one of the following:

  • True
  • False

Explanation

Question 17 of 30

1

17) RDBMSs enforce integrity rules automatically.

Select one of the following:

  • True
  • False

Explanation

Question 18 of 30

1

18) Referential and entity integrity are two names for the same thing.

Select one of the following:

  • True
  • False

Explanation

Question 19 of 30

1

19) The SELECT operator yields a vertical subset of a table.

Select one of the following:

  • True
  • False

Explanation

Question 20 of 30

1

20) Tables must have the same attribute characteristics (the columns and domains must be compatible) to be used in a UNION.

Select one of the following:

  • True
  • False

Explanation

Question 21 of 30

1

21) The DIFFERENCE operator subtracts one table from the other.

Select one of the following:

  • True
  • False

Explanation

Question 22 of 30

1

22) In a natural join, the column on which the join was made occurs twice in the new table.

Select one of the following:

  • True
  • False

Explanation

Question 23 of 30

1

23) A left outer join on tables CUSTOMER and AGENT yields all of the rows in the CUSTOMER table, including those that do not have a matching value in the AGENT table.

Select one of the following:

  • True
  • False

Explanation

Question 24 of 30

1

24) The DIVIDE operation uses one single-column table (e.g., column "a") as the divsor and one two-column table (e.g., columns "a" and "b") as the dividend.

Select one of the following:

  • True
  • False

Explanation

Question 25 of 30

1

25) A data dictionary contains metadata-data about data.

Select one of the following:

  • True
  • False

Explanation

Question 26 of 30

1

26) A data dictionary is sometimes described as :the database designer's database" because it records the design decisions about tables and their structures.

Select one of the following:

  • True
  • False

Explanation

Question 27 of 30

1

27) Current relational database software generally provides only a system catalog (and not a data dictionary).

Select one of the following:

  • True
  • False

Explanation

Question 28 of 30

1

28) The one-to-many (1:M) relationship is easily implemented in the relational mode by putting the foreign key of the "1" side in the table of the "many" side as a primary key.

Select one of the following:

  • True
  • False

Explanation

Question 29 of 30

1

29) As rare as 1:! relationships should be, certain conditions absolutely require their use.

Select one of the following:

  • True
  • False

Explanation

Question 30 of 30

1

30) DBMSs use indexes for many different purposes.

Select one of the following:

  • True
  • False

Explanation