Chap2&3 Flashcards
A person, object, or event of importance to the organization.
Entity
TRUE OR FALSE
Entities that the organization wants to store data about typically becomes a database table.
TRUE
What are the three types of entity?
- Entity Instance
- Regular Entity
- Weak Entity
This is a type of entity which is also called a strong entity?
Regular Entity
An entity which depends on other entity for its existence?
Weak Entity
A particular member of the entity type
entity instance
An entity which has its own attribute
Regular Entity
These are characteristics of an entity
Attributes
TRUE OR FALSE
Attributes typically becomes fields in the entity’s database table.
TRUE
This is an association between two or more entities.
Relationship
Enumerate the 7 classifications of Attributes.
- Key Attribute
- Simple Attribute
- Composite Attribute
- Single Valued Attributes
- Multi Valued Attributes
- Stored Attribute
- Derived Attribute
This is a set of permissible values that an attribute can take.
Domain Attribute
The attribute which is unique for every entity instance.
Key Attribute
If an attribute cannot be divided into simpler components.
Simple Attribute
If an attribute can be split into components
Composite Attribute
If an attribute can take only a single value for each entity instance
Single Valued Attributes
If an attribute can take more than one value for each entity instance.
Multi-Valued Attributes
An attribute which need to be stored permanently.
Stored Attribute
An attribute that can be calculated or derived based on other attributes.
Derived Attribute
One to one entity relationship is a common type of relationship.
FALSE
*not a common type
Cardinality of relationship
One entity is related to only one other entity of a particular type.
One to One (1:1) Entity Relationship
Cardinality of Relationship
This is the most common type of relationship.
One to Many (O:M) Entity Relationship
An example of this relationship is :
A supplier can supply more than one product to a company.
One to Many Entity Relationship
One entity can be related to more than one other entity.
One entity can be related to more than one other entity, and those entities can be related to multiple entities of the same type as the original entity.
Many to Many (M:M) Entity Relationships
What are the 4 Cardinality of Relationship?
- One to One Entity Relationship
- One to Many Entity Relationship
- Many to One Entity Relationship
- Many to Many Entity Relationship
This is a component of DBMS that stores the definition of data characteristics and relationship.
The Data Dictionary
The Data Dictionary is also known as ___________.
Data Repository System
Data Dictionary contains all data definitions in a database, including what?
*table structures
*Security information (passwords, etc)
*Relationships between the tables in the database
*Basic information about each table, such as the current number of records
The Data Dictionary contains any of the data in the tables?
FALSE
- does not contain
The Data dictionary does not contain meta data, which information about the database tables.
FALSE
*does contain metadata
The data dictionary or data repository system ensures that the data entered into the database does not violate any specified criteria.
TRUE
The two types of Data dictionary are integral and stand alone?
FALSE
*Integrated
*Stand-Alone
Difference of integrated DD and Stand-alone DD?
Integrated- built in the data dictionary
Stand Alone - this is more flexible
Enumerate the 6 Classification of Database Management System.
- Based on Data Model
- Based on Number of Users
- Based on Database Distribution
- Based on Cost of Database
- Based on Usage
- Based on Flow Control
This defines the logical and physical structure of the database.
Based on Data Model
In here, the data is organized in tables related by common fields. In addition, it is most widely used database model today.
The Relational Database Model (RDBMS)
Give the properties of Relational Database
ACID
Atomicity
Consistency
Isolation
Durability
Organizes data in a tree structure.
Typically a one to many relationship between data entities.
Hierarchical Database
Hierarchical Database is an inverted tree (parent-children relationship)
TRUE
This allows both one to many and many to many relationships between data elements
Network Database
What is ERD?
Entity Relationship Diagram
It represents data using objects and relationships among these objects.
Entity Relationship Model
What do you call the extension of ER Model?
The object-oriented Database Model
In Object-Oriented Database Model, database system in which multiple types of data are stored as objects along with their related code.
TRUE
In OODM, information can be retrieved using queries.
FALSE
*objects can be retrieved
What is OQL?
Object query language
The data items or objects of the same kind might have a different set of attributes.
Semistructured Data Model
What is XML?
Extensible Markup Language
This represents the semistructured data?
Extensible Markup Language
What are the two types of database systems based on the number of users?
- Single User Database System
- Multiuser Database System
Single User Database System FACTS
* located on a single computer
*designed to be accessed by one user
*widely used for personal applications and very small businesses.
TRUE
This database system is designed to be accessed by multiple users (most business databases today)
Multiuser Database System
What are the database systems under database distribution?
Centralized and Distributed Database System
This database system is located on a single computer such as a server or mainframe.
Centralized Database System
The data is physically divided among several computers connected by a network, but the database logically looks like it is a single database.
Distributed Database System
The Three types of DBMS based on their costs are:
- Low Cost DMBS
- Medium Cost DBMS
- High Cost DBMS
Database can be sold in the form of licenses.
TRUE
MySQL and PostgresSQL are free DBMS
TRUE
The cost of these systems vary from $100 to $3000.
Low Cost DBMS
The cost varies from $10000 - $100000
Medium Cost DBMS
The cost is more than $100000
High Cost DBMS
What is OLTP??
Online Transaction Processing
OLTP supports a larger number of transaction.
TRUE
This database is designed to meet the need of as many applications as possible.
General-Purpose DBMS
It is designed for a specific application and it can not be used for another application without performing any major changes.
Special Purpose DBMS
Active DBMS is a data-driven system or event-driven system where the control flow between the application and DBMS is based on the occurrence of an event.
TRUE
The user or the application program is responsible to initiate the operation.
Passive DBMS
In here, data is stored in hard drives.
Disk-based systems
Passive DBMS is also called as Program driven system.
TRUE`
IN Memory Databases. TRUE OR FALSE
Data is not stored in the main memory.
FALSE
*data is stored
IN Memory Databases. TRUE OR FALSE
This is dramatically slower than disk-based databases.
FALSE
- dramatically faster
IN Memory Databases. TRUE OR FALSE
It is very essential to have good backup procedures.
TRUE
IN Memory Databases. TRUE OR FALSE
These are used in high-end systems where performance is crucial and in small footprint embedded applications.
True
This is a combination of two or more database types or models.
Hybrid Database Models
This can store and retrieved both XML data and relational data
Hybrid XML / Relational Database
This is typically hosted on a cloud database provider’s servers that is accessible to users via the web.
Cloud Databases
What are example of Cloud database in Use.
- Information retrieval
- Support and facilitate e-commerce
- Cloud databases allow web pages to be dynamic web pages.
data to be accessed and displayed on a web page is often stored in a database (ex: search sites.)
information retrieval
Display product information, pricing, customer information, shopping cart contents, etc.
Support and facilitate e-commerce.
Collection of attribute values
Tuples
