UTA INSY 3304 EXAM QUESTIONS AND ANSWERS
LATEST UPDATE (ALREADY GRADED A+)
Relational adv
structural independence is promoted by use of independent tables
-tabular view improves simplicity
-ad hoc query based on SQL
Relational disadv
requires substantial hardware and system software overhead
-simplicity makes it easy for untrained people to use tools poorly, and produce data anomalies
-may promote island of info problems because ind and departments can easily develop own apps
entity relationship adv
visual modeling yield exceptional simplicity
-visual simplicity makes effective communication tool
-integrated with dominant relational model
entity relationship disadv
limited constraint repr
-limited relationship repr
-no data manipulation language
-loss of info occurs when attributes are removed from entities to avoid crowded display
object oriented adv
semantic content is added
-visual rep includes semantic content
-inheritance promotes data integrity
object oriented disavantages
slow development of standards caused vendors to supply their own enhancements thus eliminating
widely accepted standard
-complex navigation system
-steep learning curve
-high sys overhead slows transactions
NO SQL adv
high scalability, availability, and fault tolerance provided
-uses low cost hardware
-supports BIG data
-key-value model improves storage efficency
, NO SQL disadv
complex programming required
-no relationship support
-no transaction integrity support
Entity
person, place, thing, or event about which data will be collected and stored
attribute
char of an entity, CUSTOMER entity would be described by attributes such as last, first name
table
resembles files conceptually and logically with rows and columns
Row
tuple, represents a single entity occurrence within entity set
column
represents an attribute, and each column has distinct name
Attribute domain
each column has specific range of values
primary key
one or more attributes that uniquely identifies each row in table
-natural(distinguish real world objects)
-surrogate(simplify identification of entity instances)
-entity integrity(no null, must be unique, so each row is unique)
Foreign key
one or more attributes whose value matches the primary key value in a related table
-Referential integrity: if foreign key contains a value it must refer to an existing valid row in related table
Super key
attribute(for combination of attributes) that uniquely identifies each row in table
candidate key
minimal super key, super key that does not contain a subset of attributes that is itself a superkey
secondary key
used for data retrieval purposes
LATEST UPDATE (ALREADY GRADED A+)
Relational adv
structural independence is promoted by use of independent tables
-tabular view improves simplicity
-ad hoc query based on SQL
Relational disadv
requires substantial hardware and system software overhead
-simplicity makes it easy for untrained people to use tools poorly, and produce data anomalies
-may promote island of info problems because ind and departments can easily develop own apps
entity relationship adv
visual modeling yield exceptional simplicity
-visual simplicity makes effective communication tool
-integrated with dominant relational model
entity relationship disadv
limited constraint repr
-limited relationship repr
-no data manipulation language
-loss of info occurs when attributes are removed from entities to avoid crowded display
object oriented adv
semantic content is added
-visual rep includes semantic content
-inheritance promotes data integrity
object oriented disavantages
slow development of standards caused vendors to supply their own enhancements thus eliminating
widely accepted standard
-complex navigation system
-steep learning curve
-high sys overhead slows transactions
NO SQL adv
high scalability, availability, and fault tolerance provided
-uses low cost hardware
-supports BIG data
-key-value model improves storage efficency
, NO SQL disadv
complex programming required
-no relationship support
-no transaction integrity support
Entity
person, place, thing, or event about which data will be collected and stored
attribute
char of an entity, CUSTOMER entity would be described by attributes such as last, first name
table
resembles files conceptually and logically with rows and columns
Row
tuple, represents a single entity occurrence within entity set
column
represents an attribute, and each column has distinct name
Attribute domain
each column has specific range of values
primary key
one or more attributes that uniquely identifies each row in table
-natural(distinguish real world objects)
-surrogate(simplify identification of entity instances)
-entity integrity(no null, must be unique, so each row is unique)
Foreign key
one or more attributes whose value matches the primary key value in a related table
-Referential integrity: if foreign key contains a value it must refer to an existing valid row in related table
Super key
attribute(for combination of attributes) that uniquely identifies each row in table
candidate key
minimal super key, super key that does not contain a subset of attributes that is itself a superkey
secondary key
used for data retrieval purposes
