WGU D427 DATA MANAGEMENT
APPLICATIONS UPDATED ACTUAL EXAM
QUESTIONS AND CORRECT ANSWERS
COMPLETE STUDY GUIDE
◉ Relational Model
Answer: Based on a tabular data structure published in 1970 and
released in 1980, standardized structures, operations, and rules.
Good for productivity and transactional applications. e.g Oracle
◉ Hierarchial Model
Answer: The tree data structure, released in 1960, has fast queries
and efficient storage. e.g IMS
◉ Network Model
Answer: The linked list data structure, released in 1970, has fast
queries and efficient storage. e.g IDMS
◉ Object Model
,Answer: Class data structure, released in 1990, has strong
integration with object-oriented programming languages. e.g
ObjectStore
◉ Graph Model
Answer: Vertex and Edge data structures, released in 1000, have
flexible schemas and are well-suited to evolving business
requirements. e.g Neo4j
◉ Document Model
Answer: The XML and JSON data structures, released in 2010, have
flexible schemas and support both unstructured and semi-
structured data. e.g MongoDB
◉ Set
Answer: Unordered collection of elements enclosed in braces
◉ Tuple
Answer: ordered collection of elements enclosed in parentheses
◉ Table
Answer: Has a name, a fixed tuple of columns, and a varying set of
rows. Also called a Relation or File.
, ◉ Column
Answer: Has a name and a data type. Also called an Attribute or
Field.
◉ Row
Answer: Unnamed tuple of values. Also called a Tuple or Record.
◉ Data Type
Answer: Named set of values. Also called a Domain.
◉ Select
Answer: Selects a subset of (or all) rows
◉ Project
Answer: Selects one or more columns
◉ Product
Answer: Lists all combination of rows of two tables
◉ Join
Answer: Combines two tables by comapring related columns
APPLICATIONS UPDATED ACTUAL EXAM
QUESTIONS AND CORRECT ANSWERS
COMPLETE STUDY GUIDE
◉ Relational Model
Answer: Based on a tabular data structure published in 1970 and
released in 1980, standardized structures, operations, and rules.
Good for productivity and transactional applications. e.g Oracle
◉ Hierarchial Model
Answer: The tree data structure, released in 1960, has fast queries
and efficient storage. e.g IMS
◉ Network Model
Answer: The linked list data structure, released in 1970, has fast
queries and efficient storage. e.g IDMS
◉ Object Model
,Answer: Class data structure, released in 1990, has strong
integration with object-oriented programming languages. e.g
ObjectStore
◉ Graph Model
Answer: Vertex and Edge data structures, released in 1000, have
flexible schemas and are well-suited to evolving business
requirements. e.g Neo4j
◉ Document Model
Answer: The XML and JSON data structures, released in 2010, have
flexible schemas and support both unstructured and semi-
structured data. e.g MongoDB
◉ Set
Answer: Unordered collection of elements enclosed in braces
◉ Tuple
Answer: ordered collection of elements enclosed in parentheses
◉ Table
Answer: Has a name, a fixed tuple of columns, and a varying set of
rows. Also called a Relation or File.
, ◉ Column
Answer: Has a name and a data type. Also called an Attribute or
Field.
◉ Row
Answer: Unnamed tuple of values. Also called a Tuple or Record.
◉ Data Type
Answer: Named set of values. Also called a Domain.
◉ Select
Answer: Selects a subset of (or all) rows
◉ Project
Answer: Selects one or more columns
◉ Product
Answer: Lists all combination of rows of two tables
◉ Join
Answer: Combines two tables by comapring related columns
