Oracle chapter 9

The "Arc Implementation" is a synonym for what type of implementation?

Supertype and Subtype Implementation

A table does not have to have a primary key.

True

Identify all of the correct statements that complete this sentence: A primary key is: (Choose Three)

A set of columns that uniquely identifies each row in a table A single column that uniquely identifies each row in a table A set of columns and keys in a single table that uniquely identifies each row in a single table

Which of the following is a valid reason for considering a Subtype Implementation?

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

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

Column

Column integrity refers to

Columns always containing values consistent with the defined data format

A foreign key cannot refer to a primary key in the same table.

False

In a physical data model, a relationship is represented as a:

Foreign Key

In a physical data model, a relationship is represented as a combination of: (Choose Two)

Foreign Key Primary Key or Unique Key

One-to-Many Optional to Mandatory becomes a _______________ on the Master table.

Mandatory Foreign 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.

Referential integrity

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

Table

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

When translating an arc relationship to a physical design, you must turn the arc relationships into foreign keys. What additional step must you take with the created foreign keys to ensure the exclusivity principle of arc relationships? (Assume that you are implementing an Exclusive Design) (Choose Two)

Create an additional check constraint to verify that one foreign key is populated and the others are not Make all relationships optional

The explanation below is an example of which constraint type? A primary key must be unique, and no part of the primary key can be null.

Entity integrity

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

False

It is possible to implement non-transferability via a simple Foreign Key Relationship.

False

One-to-One relationships are transformed into Check Constraints in the tables created at either end of that relationship.

False

One-to-One relationships are transformed into Foreign Keys in the tables created at either end of that relationship.

False

Relationships on an ERD can only be transformed into UIDs in the physical model?

False

When an Arc is transformed to the physical model every relationship in the Arc becomes a mandatory Foreign Key.

False

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

False

In a physical model, many to many relationships are resolved via a structure called a(n): ________________

Intersection Table

The transformation from an ER diagram to a physical design involves changing terminology. Entities in the ER diagram become __________ :

Tables

Two entities A and B have an optional (A) to Mandatory (B) One-to-One relationship. When they are transformed, the Foreign Key(s) is placed on:

The table B

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

True

Attributes become columns in a database table.

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

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.

User-defined integrity

Why would this table name NOT work in an Oracle database? this_year_end+next_year

The Plus sign + is not allowed in object names.

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

The Primary Key

Identify all of the incorrect statements that complete this sentence: A primary key is...(Choose three)

Only one column that must be null. A single column that uniquely identifies each column in a table. A set of columns in one table that uniquely identifies each row in another table.