Database Design Section 9 Quiz

Which of the following is a valid reason for considering a Subtype Implementation? - The resulting table will reside in a single database and be used by just ONE user. - Most of the relationships are at the supertype level. - Business functionality, business rules, access paths, and frequency of access are all very different between the subtypes. - The common access paths for the supertypes are different.

- Business functionality, business rules, access paths, and frequency of access are all very different between the subtypes.

In a physical data model, a relationship is represented as a combination of: (Choose Two) - Column - Foreign Key - Check Constraint or Unique Key - Primary Key or Unique Key

- Foreign Key - Primary Key or Unique Key

The explanation below is an example of which constraint type? The value in the dept_no column of the EMPLOYEES table must match a value in the dept_no column in the DEPARTMENTS table. - Column integrity - User-defined integrity - Entity integrity - Referential integrity

- Referential integrity

The explanation below is an example of which constraint type?If the value in the balance column of the ACCOUNTS table is below 100, we must send a letter to the account owner which will require extra programming to enforce. - Column integrity - User-defined integrity - Entity integrity - Referential integrity

- User-defined integrity

In a physical data model, an attribute becomes a _____________.

Column

A foreign key cannot refer to a primary key in the same table. True or False?

False

Foreign keys must be null. True or False?

False

In a physical data model, an entity becomes a _____________.

Table

A barrred Relationship will result in a Foreign Key column that also is part of:

The Primary Key

An "Arc Implementation" can be done just like any other Relationship - you simply add the required Foreign Keys. True or False?

False

The Oracle Database can implement a many to many relationship. You simply create two foreign keys between the two tables. True or False?

False

To resolve a many to many relationship in a physical model you create a(n) ___________________?

Intersection Table

An Arc is transformed to the physical model by adding a foeign Key for every relationship in the Arc. True or False?

True

When mapping supertypes, relationships at the supertype level transform as usual. Relationships at the subtype level are implemented as foreign keys, but the foreign key columns all become optional. True or False?

True

In an Oracle database, why would the following table name not be allowed 'EMPLOYEE JOBS'?

You cannot have spaces between words in a table name