What is Logical data independence?

Immunity of the external schemas to change

What are Legal Relations?

Relations that satisfy constraints

What is a Data Model?

Theory describing how a database is structured and used

Data models comprise which three components?

Integrity constraints, Manipulative, Structural

What is Availability in CAP Theorem?

Every request receives a response

Transactions results in a state obtained serial execution

What is a Foreign key?

Matches a key within another relation

What is a Relationship?

How entities are related to one another

What is a Base Relation?

Physically stored in the database

What is a Degree of a Relationship?

The number of participating entity types in a relationship

What is a Database Schema?

Blueprint of how a database is constructed

A mathematical term for a two-dimensional table of data

Guarantees all operations in the set occur or nothing occurs

Committed transactions are permanent

Transactions bring the DB from one valid state to another

What is Physical data independence?

Immunity of the conceptual schema to change

What is a Primary key?

Uniquely identifies a tuple in a relation

What is Partition Tolerance in CAP Theorem?

Continuous operation in the event of communication loss

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CHI2550: ICT Set 2-3

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Questions 24

Answers

1
What is a Tuple?
A named column of a relation
The number of attributes it contains
A mathematical term for a two-dimensional table of data.
A row of a relation
2
What is S in BASE?
Satisfied-security
Soft-state
Static-system
Soft-status
3
What is Logical data independence?
Immunity to change definition and organization of the data
Immunity of the external schemas to change
The description of a database
Same attribute is repeated in two or more records
4
What are Legal Relations?
Relations that satisfy constraints
Undesired side-effects
Limitation or restrictions on a relation
Same data can be expressed on multiple tuples
5
What is a Data Model?
Ensures the data is accurate
Theory describing how a database is structured and used
A set of rules by which the database will be constructed
Defines the types of operations that are allowed on the data
6
Data models comprise which three components?
Integrity constraints
Manipulative
Structural
Parent-child relationships
7
What is Availability in CAP Theorem?
Every request receives a response
All nodes see the same data
Participating nodes coordinate before committing
Continuous operation in the event of communication loss
8
What is Isolation?
Post-condition, transformation
Pre-condition, transformation
Transactions results in a state obtained serial execution
Ensures one valid state to another
9
What is an Attribute?
A named column of a relation
The number of attributes in a relation
A mathematical term for a two-dimensional table of data.
A row of a relation
10
What is a Foreign key?
How entities are related to one another
Matches a key within another relation
The number of participating entity types in a relationship
Uniquely identifies a tuple in a relation
11
What is a Relationship?
A relationship between two entity types
The number of participating entity types in a relationship
How entities are related to one another
A relationship between instances of a single entity
12
What is a Base Relation?
Physically stored in the database
Logically stored in the database
How entities are related to one another
Conceptually stored in the database
13
What is a Degree of a Relationship?
A mathematical term for a two-dimensional
Simultaneous relationships among three entity types
A relationship between instances of a single entity
The number of participating entity types in a relationship
14
What is a Database Schema?
Describes how data are physical stored in secondary storage.
Describes different external views of the database.
Describes different internal views of the database.
Blueprint of how a database is constructed
15
What is a Relation?
A row in a relation
A mathematical term for a two-dimensional table of data
How entities are related to one another
A named column in a relation
16
What is Atomicity?
Transactions bring the DB from one valid state to another
Guarantees all operations in the set occur or nothing occurs
Post-condition transformation
Pre-condition transformation
17
What is Durability?
All nodes see the same data.
Every request receives a response
Single user has exclusive access to the data until released
Committed transactions are permanent
18
What is BA in BASE?
Basic Availability
Basically Unavailable
Basic Atomicity
Basically Available
19
What is Consistency?
Transactions results in a state obtained serial execution
Guarantees all operations in the set occur or nothing occurs
Prevents partial updates to the database occurring
Transactions bring the DB from one valid state to another
20
What is Consistency in CAP Theorem?
Continuous operation in the event of communication loss
All nodes see the same data
Participating servers must coordinate before committing
Every request receives a response
21
What is E in BASE?
Eventually-consistent
Eventually-concurrent
Event-concurrency
Event-consistency
22
What is Physical data independence?
Immunity of the external schemas to change
Immunity of the conceptual schema to change
The description of a database
Immunity to change definition and organization of the data
23
What is a Primary key?
The number of participating entity types in a relationship
How entities are related to one another
Uniquely identifies a tuple in a relation
Matches a key within another relation
24
What is Partition Tolerance in CAP Theorem?
Every request receives a response
Continuous operation in the event of communication loss
Availability of data in the presence of multiple failures
All nodes see the same data

CHI2550: ICT Set 2-3 Flashcards | StudBud