Exam 6: Relational Database Design

On average, 99 out of 100 sales have related cash receipts (there is usually 1 sale out of 100 that either results in a sale return or becomes a bad debt). On average, 45 out of 100 cash receipts are related to sales (the company also generates revenue through rentals, which it keeps track of in a separate entity set; 50 out of 100 of its cash receipts result from those rentals, the other 5 out of 100 result from financing events). Considering both redundancy and load, which of the following would be the best relational table implementation solution?

In relational database design, the definition of a fact is:

You will be able to join two fields of different data types together as long as the data values match exactly.

Describe the two ways in which the one-fact-one-place rule could be violated and explain how to prevent or fix the violations.

What is the first step in converting a conceptual entity-relationship model into relational database tables?

Disregarding minimum cardinalities, when converting conceptual models into relational tables

In the relational database model each table represents either an entity or a relationship between entities.

Entity integrity refers to a primary key that will allow null values.

Convert the following conceptual model into a set of minimal relational database tables. Underline primary keys and write FK next to foreign keys in your tables. List any assumptions you make with regard to load for any of the tables.

Which example relational tables contain data that best represents the cardinalities shown in the following conceptual model?

If you have two entities that are related with a cardinality pattern of (1,1) - (1,N) how many tables must you include in a correctly designed database to represent this entity-relationship cluster?

To communicate to Microsoft Access the fact that a primary key of one entity has been posted as a foreign key in another table, one must simply use the same field name and data type in each of the two tables.

An auditor examined the database for Trent's Textiles Corporation. During her examination, she noticed two cash disbursements in the Cash Disbursements table had blanks (null values) in the vendor number field. Assuming no data entry error has occurred, what is the most plausible explanation for these blanks?

The order in which columns are placed in a relational database table is crucial to maintain referential integrity.

What is the correct action to take when converting a conceptual entity-relationship model into relational tables for a relationship that has a participation cardinality pattern of (1,1) - (1,1)?

A concatenated relationship key contains fields from one relational database table.

The rule for converting relationships for which the maximum participation cardinalities are many for both entities is to post the primary key of either entity into the table of the other entity.

In Microsoft Access, enabling the "Cascade Update Related fields" option in the relationship layout accomplishes which of the following:

Fields for which the data type is "text" may be used in calculations in queries.

Columns in a relational database structure are also called ______ ______, _______ or _______.