Physical Database Design

Selecting a data type involves which of the following?

• Maximize storage space

• Represent most values

• Improve data integrity

• All of the above.

The blocking factor is:

What is the best data type definition for Oracle when a field is alphanumeric and has a length that can vary?

• VARCHAR2

• CHAR

• LONG

• NUMBER

A rule of thumb for choosing indexes for a relational database includes which of the following?

• Indexes are more useful on smaller tables.

• Indexes are more useful for coloumns that do not appear frequently in the WHERE cluse in queries.

• Do not specify a uniqe index for the primary key of each table.

• Be careful indexing attributes that have null values.

Which of the following is an advantage of partitioning?

• Complexity

• Inconsistent access speed

• Extra space

• Security

Which of the following are integrity controls that a DBMS may support?

• Assume a default value in a field unless a user enters a value for that field.

• Limit the set of permissible values that a field may assume.

• Limit the use of null values in some fields.

• All of the above.

A secondary key is

If a denormalization situation exist with a one-to-one binary relationship, which of the following is true?

• All fields are stored in one relation.

• All fields are stored intwo relations.

• All fields are stored in three relations.

• All fields are stored in four relations.

Which of the following improves a query's processing time?

• Write complex queries

• Combine a table with itself.

• Query one query within another.

• Use compatible data types.Use compatible data types.

Which of the following is not a factor to consider when switching from small to large block size?

• The length of all of the fields in a table row.

• The number of columns

• Block contention

• Random row access speed