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Database Design
Database Design
83
Computer Networking
Undergraduate 1
10/10/2014
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Term
Ch.4
 Definition
Term
How do you indicate the primary keys when converting tables from an ERD?
 Definition
Underline the attribute that serves as primary key in each table.
Term
If the primary key of one table appears as an attribute  in another table, then this attribute is called a
 Definition
Foreign key.
Term
How do we convert a "one-to-many" relationship to a set of tables?
 Definition
Take the primary key of the one side, and put it into the many side of the relationship.
Term
Which of the following is false about foreign keys?
 Definition
1)Foreign keys create relationships between tables
2)Foreign key values must be a subset of the corresponding primary key values

3)Foreign key fileds must have the same name as the corressponding primary key names.

 

4)Foreign keys are shown using dashed underline when we convert the ERD to a set of tables.
Term
How do we conert a "many-to-many" relationship to a set of tables?
 Definition
Create a composite primary key by combining the primary keys of each entity in the intersection table.
Term
Intersection entities are created when we convert _____
 Definition
Many to many relationships & ternary relationships.
Term
Ch.1
 Definition
Term
Access security
 Definition
Controlling user and application access to data by allowing or disal-
lowing different activities
Term
Authentication method
 Definition
A way of identifying a client before authorizing access to
database resources. The most common authentication methods are based on user
names and associated passwords
Term
consumer audience
 Definition
Data consumers — the people or applications who need access
to data and who use data in some manner.
Term
core business
 Definition
A business’ or organization’s primary activity. The organization’s justi-
fication for existence.
Term
Data or raw data
 Definition
stream of facts that is not organized or arranged into a form that people can understand or use.
Term
Data access
 Definition
The process of allowing users or applications to retrieve data from a
database
Term
Data accuracy
 Definition
Ensuring that data is accurate and correct.
Term
Data consumer
 Definition
Person, department, or application accessing and using data. See also
consumer audience.
Term
Data query
 Definition
Term commonly used to refer to data access.
Term
Data security
 Definition
Processes and procedures implemented with the goal of keeping data
safe. Basic data security categories are access security and physical security.
Term
database
 Definition
An ordered collection of related data elements intended to meet the infor-
mation needs of an organization and designed to be shared by multiple users.
Term
Fault-tolerant disk system
 Definition
Physical data storage method designed to avoid data loss or
errors in case of hardware failures.
Term
Information
 Definition
Data that has been organized in such a way as to be meaningful and useful
to people.
Term
Mirror image
 Definition
An exact duplicate of a database or other data file.
Term
Physical security
 Definition
Protecting data against physical corruption or loss; typically involves
protecting the server, ensuring the storage media and duplicating data.
Term
Surface area
 Definition
A term referring to how exposed an database is to access and
manipulation.
Term
Ch.4
 Definition
Term
Composite Key
 Definition
key defined by multiple columns
Term
Data integrity
 Definition
Ensuring that data values are properly entered and maintained.
Term
Data normalization
 Definition
A methodology for organizing attributes into tables so that redun-
dancy among the nonkey attributes is eliminated.
Term
Decomposition process
 Definition
Another term for the data normalization process. Also called
“non-loss decomposition.”
Term
Defining association
 Definition
A means of expressing that the value of one particular attribute
is associated with a single, specific value of another attribute.
Term
Determinant attribute
 Definition
The attribute in a defining association whose value determines
the value of the attribute on the right side of the association.
Term
Exception conditions
 Definition
Less commonly used normal forms.
Term
First normal form
 Definition
Each attribute value is atomic, that is, no attribute is multivalued. Get rid of repeating groups of data by making another table. Also break up name into firstname lastname.
Term
Functional dependency
 Definition
See Defining association.Defining association -  A means of expressing that the value of one particular attribute
is associated with a single, specific value of another attribute.
Term
Joining
 Definition
Combining the data from two tables based on linking columns.
Term
Non-loss decomposition
 Definition
Normalization process in which neither data nor relation-
ships are lost.
Term
Normal forms
 Definition
Defined rules for data normalization.
Term
Null value
 Definition
An undefined value, usually used to identify that no value is provided for
that attribute
Term
Partial funcitonal dependency
 Definition
A dependency where data is dependent on part of the
primary key.
Term
referential integrity
 Definition
Another name for relational integrity, referring to the fact that
you are maintaining the relationship between referencing and referenced tables.
Term
relational integrity
 Definition
Another name for relational integrity, referring to the fact that
you are maintaining the relationship between referencing and referenced tables.
Term
second normal form
 Definition
Every nonkey attribute must be fully functionally dependent on
the entire key.
Term
third normal form (3NF)
 Definition
Referring to a database normalized to the third normal form.
Transitive dependencies are not allowed.
Term
Transitive dependency
 Definition
One nonkey attribute is functionally dependent  on another non key attribute, that is functionally dependent on a primaryk key.. C relies on b and b relies on a. Thus C is transitively dependent.
Term
Ch.2
 Definition
Term
Data repository or Database
 Definition
Storage unit where the physical or actual data is kept
Term
Database management system (DBMS)
 Definition

Manages storage, use, and protection of data.

DBMS is not a database itself

Major DBMS vendors: Oracle, MySQL, Microsoft SQL server
Term
Types of databases
 Definition
Production, decision support, and mass deploymment databases.
Term
Production databases or Transactional databases
 Definition
[image]
Term
Decision support databases
 Definition
[image]
Term
Mass Deployment databases
 Definition
[image]
Term
Hierarchical Database
 Definition

 

Mainframe-based databases.

 

Organizes data physically in form of a tree or hierarchy of nodes (one parent per child).

 

A child has one parent; a parent can have multiple children

 

Pointers” connect parent and child nodes.

 

nomplicated, and costly to access, maintain, and update data.[image]
 

 
Term
Network database
 Definition

 

nMainframe-based, complex, legacy databases.

 

nOvercomes the limitation of hierarchical databases:

 

qA child node can have more than one parent node

 

nPointers connect “members” and “owners”

 

nSame problems as hierarchical – complex and costly.

 
Term
Relational Database
 Definition

 

 

Organizes data in the form of tables.

 

Data connected across tables logically using foreign keys.

 

Simpler to understand, access, and maintain data.

 

Preferred database standard today.

Each table represents an “entity”
qEach column represents an attribute (or field)
qEach row (or tuple) represents a data “instance”
Primary key: One (or more) attribute(s) that uniquely identifies each instance
Tables are connected through logical “relationships”
nRelationships are implemented using “foreignkeys”

 

 
Term
Object-Oriented database
 Definition

 

Data organized as objects

 

Better representation of real-world

 

Supports large pictures and videos
(relational databases support them too)

 

Not commonly used

 

Object-oriented relational database:

 

Integrates features of both

 

There is a blurry line between pure relational and object-oriented relational databases

 
Term
Data Dictionary
 Definition

 

Stores the structure of data (e.g., field names, sizes, data types, etc.)

 
Term
Components of DBMS
 Definition
Database engine, query processor, forms generator(Optional), report writer.(optional)
Term
Database engine
 Definition

 

§Heart of the DBMS

 

§Coordinates tasks performed by all other DBMS components.

 

§Tracks where data is located, how it is accessed and updated.

 

§Responsible for data access, security, accuracy.

 
Term
Query processor:
 Definition
query processor handles parsing, optimizing and processing queries.
Term
Forms generator
 Definition

 

§Creates screen layouts or forms for data input or display from/to users.

 
Term
Report writer
 Definition
Used for generating reports (using queries) for display or printing.
Term
Database Life cycle
 Definition
[image]
Term
1. Data modeling
 Definition

interview users, or look at problem description to identify:

entities, attributes, relationships

Create a entity relationship diagram (ERD)
Term
2. Logical Database design
 Definition
Map ERD into tables, normalize tables as desired, output a set of 3rd normal form relations.
Term
3. physical database design:
 Definition

specify business rules primary key, foreign key, referential integrity.

Output implemntable tables with complete meta data.
Term
4. Database implementation
 Definition

 

qSelect DBMS, storage mechanisms, access methods, data update strategy, database distribution strategy (if needed).

 

qCreate database tables with fields and primary keys.

 

qSpecify relationships between tables via foreign keys.

 

qLoad/import data into the above tables.

 

qCreate user documentation (meta-data).

 

qOutput: A fully functional relational database, user documentation.

 
Term
5. Database maintenance
 Definition

 

qModify data structure as needed (indefinitely).

 

qModify application programs as needed.

 

qMonitor database performance in real time.

 

qPerform routine database upgrades.

 
Term
Ch.3
 Definition
Term
Entity-Relationship model (ERD)
 Definition
a visual representation of entities, their attributes, and the realtionships between entities.
Term
Entity
 Definition

People, places, objects, things, events, or
concepts about which data is being collected. (NOUNS)

Represented as a rectangle in ERD


[image]
Term
Attribute
 Definition

Property or characteristics of entities (or

relationships). Do not use space character when creating attributes.
Term
Relationship
 Definition

 

Business rules governing associations

between entities.
Represented by a diamond on ERD
Each entity has to have at least one relationship with another entity.
Describe associations between entities. 
Represent the BUSINESS RULES! 
VERBS that link entities 
Relationships involve: organizational policies,
rules, and regulations
 Examples:
Every customer is associated with a salesperson An instructor cannot teach more than one course

 
Term
Primary key
 Definition
[image]
Term
Entity instance or record
 Definition
A single example of an entity. Ex. entity employee, instance one employee.
Term
unary relationship
 Definition
[image]
Term
Binary Relationship
 Definition
[image]
Term
Ternary Relationship
 Definition
[image]
Term
Cardinality
 Definition

Value setting the maximum number of entities that can be involved in a
particular relationship.


[image]
Term
Modality
 Definition

Value setting the minimum number of entities that can be involved in a
particular relationship.

 
Term
Reading an ERD
 Definition
[image]
Term
Cardinality and Modality
 Definition
[image]
Term
intersection Data
 Definition
[image]
Term
Associative entity
 Definition
Relationship between two entities.
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