Database Design Exam

Front 1

If a logical model meets 4NF what can we assume about the model

Back 1

Undesirable functional dependencies have been resolved

Front 2

Super key

Back 2

Unique

Front 3

Candiate key

Back 3

Unique and irreducible

Front 4

Non-trivial join dependencies

Back 4

Exist when there are 3 primary keys (3 underlined attributes)

Front 5

Which syntax includes all the tuples from the left table and only matching tuples from the right

Back 5

Left join

Front 6

Which syntax includes all tuples matching the left and right table

Back 6

Inner join

Front 7

Which syntax includes all the tuples from both left and right, plus the matching information

Back 7

Full outer join

Front 8

To meet the requirements for minimal cover, we could transform A-> (B,C) into how many dependencies?

Back 8

2

A ->B

A->C

Front 9

Normalization

Back 9

Validates a database design

Front 10

The bottom-up approach for determining the candidate keys of a relation by iteratively adding attributes together to evaluate which combinations of attributes and functional dependencies can fully recreate the original relation is referred to as

Back 10

Synthesis

Front 11

To preserve information during decomposition the database should

Back 11

Use lossless joins

retain all attributes

retail all functional dependencies

retail all business rules

Front 12

(Ensures that the value in a column meets a specific condition) Semantic Integrity constraints that deal with attribute-level conditions that are retained through the logical model are generally enforced by

Back 12

Check constraints

Front 13

combination of a NOT NULL and UNIQUE. Ensures that a column (or combination of two or more columns) have a unique identity which helps to find a particular record in a table more easily and quickly

Back 13

PRIMARY KEY constraint

Front 14

Ensures that each row for a column must have a unique value

Back 14

UNIQUE constraint

Front 15

Indicates that a column cannot store NULL value

Back 15

NOT NULL constraint

Front 16

Normalization accomplished through decomposition does what?

Back 16

Changes undesirable functional dependencies into desirable ones

Front 17

conceptual database design

Back 17

1. evaluates relationships between entities

2. mostly based on intuition and semantics

3. Uses symbols and diagrams similar to flowcharts

4. typically retains some undesirable redundancy which can cause anomalies

5. Technology dependent

Front 18

logical database design

Back 18

1. Evaluates relationships between attributes

2. Rooted in relational algebra

3. symbols typically appear more like equations

4. normalization eliminates almost all undesirable redundancies

5. Influenced by the limitations of the DBMS

Front 19

From a conceptual perspective, violating a normal form requirement means

Back 19

Two different relations have been mistakenly specified as a single relation

Front 20

If a table has resolved all anomalies caused by undesirable functional dependencies what normal form is it in

Back 20

3NF/BCNF

Front 21

What is required to describe the conceptual necessity of 4NF

Back 21

It is possible to have anomalies due to 2 independent relationships between attributes with the same determinant

Front 22

A table with 4 attributes that are all part of the primary key is in at least what normal form?

Back 22

3NF/BCNF

Front 23

The entity integrity constraint possessed by a primary key and not a by a superkey or candidate key is?

Back 23

Not null

Front 24

Using a surrogate key does which of the following

Back 24

Provides a way to uniquely identify all tuples

Front 25

A table in 3NF has..

Back 25

1. no multi-value attributes

2. No undesirable partial attributes

3. No undesirable transitive dependencies

4. eliminantes redundancy caused by undesirable functional dependencies