WGU D426 V2 - 2026-2027 Comprehensive Frequently Tested Questions With Verified
Multiple Choice and Conceptual Actual 100% Correct Detailed Answers
Guaranteed Pass!!Current Update!!
The relationship (within the relation) that describes how
the value of one attribute may be used to find the value of Functional Dependency
another attribute.
An attribute that can be used to find the value of another
Determinant
attribute in the relation.
Value can be used to find the value of every other non-key
Candidate Key
attribute in the table. Unique and minimal.
Define & manage database structures DDL
Adding, deleting, and modifying data - Manipulates data
DML
stored in a database.
Used to create user accounts, manage permissions and
DCL
access.
Includes CREATE, DROP, ALTER, TRUNCATE, RENAME DDL
A view created and stored on the database. Underlying
data is changed and also updated in this view. Uses mem- Materialized View
ory space.
Not stored in memory. Only computed when used or
Virtual View
accessed.
The data about the data. Describes elements such as
Metadata
columns, names, and data type.
Ordered collection of elements in parentheses. Tuple
% of table rows selected by a query Hit Ration
Reads blocks directly, without accessing an index. Table Scan
Reads index blocks sequentially in order to locate the
Index Scan
needed table blocks.
Database repeatedly splits the index in two until it finds a
Binary Search
match.
, WGU D426 V2 - 2026-2027 Comprehensive Frequently Tested Questions With Verified
Multiple Choice and Conceptual Actual 100% Correct Detailed Answers
Guaranteed Pass!!Current Update!!
Database object that maps one or more tables to a single
Tablespace
file.
Specifies tables, columns, and keys. Implements database
requirements in a specific database system. Also called a Logical Design
schema.
Specifies indexes, table structures, and partitions. Speci-
Physical Design
fies how tables are organized on storage media.
Components of a computer system and the relationships
Architecture
between components.
Interact directly with database users and administrators
and send queries to the query processor. Includes Con- Tools
nectors & APIs, Workbench, and utility programs.
Interprets queries. Compiles queries into low-level in-
structions for the storage engine. Creates a plan to modify
Query Processor
the database or retrieve data, and returns query results to
the application.
Link between tools and query processor Connection
Creates connections and manages communication be-
Connection Manager
tween tools and query parser.
Translates the query processor instructions into low-level
Storage Engine
file system commands that modify or retrieve data.
Accesses data on storage media. Data stored on storage
media and organized in files. Contains 3 types of data:
- User data (tables & indexes) - Log files (record of any
File System
changes) - Data dictionary (aka: catalog directory of ta-
bles, columns, keys, indexes in a relational database). One
row for each database object.
Stores reusable information in main memory. Cache Manager
, WGU D426 V2 - 2026-2027 Comprehensive Frequently Tested Questions With Verified
Multiple Choice and Conceptual Actual 100% Correct Detailed Answers
Guaranteed Pass!!Current Update!!
Retains data blocks from the file system for possible reuse. Butter Manager
Arranged in hierarchy Multi-tier architecture
Multi-tier consisting of web browsers and web servers
Web architecture
communicating over the internet.
A software layer that emulates a complete, independent
Virtual Machine
computing environment.
A database ottered as a PaaS cloud service. Cloud Database
A statement or proposition from which another statement
Premise
is inferred.
Multiple processors managed by a single operating sys-
tem instance.
Shared memory - share the same memory and storage
Parallel Computer
media.
Shared storage - share storage media only.
Shared nothing
Group of computers connected by LAN or WAN Node
Group of nodes connected by a LAN, managed by sep-
arate operating system instances. Similar to a parallel Cluster
computer.
Runs on a parallel computer or cluster Parallel Database
Runs on multiple computers connected by a WAN Distributed Database
Updates data on multiple nodes of a distributed database.
Two-phase commit (nodes receive notice of update, store
update in log, send confirmation, then receive commit). Distributed Transactions
Either all nodes or no nodes must be successfully updat-
ed.
Updates data on a single node of a distributed database.
Local Transaction
Databases that use this are called "eventually consistent".
Multiple Choice and Conceptual Actual 100% Correct Detailed Answers
Guaranteed Pass!!Current Update!!
The relationship (within the relation) that describes how
the value of one attribute may be used to find the value of Functional Dependency
another attribute.
An attribute that can be used to find the value of another
Determinant
attribute in the relation.
Value can be used to find the value of every other non-key
Candidate Key
attribute in the table. Unique and minimal.
Define & manage database structures DDL
Adding, deleting, and modifying data - Manipulates data
DML
stored in a database.
Used to create user accounts, manage permissions and
DCL
access.
Includes CREATE, DROP, ALTER, TRUNCATE, RENAME DDL
A view created and stored on the database. Underlying
data is changed and also updated in this view. Uses mem- Materialized View
ory space.
Not stored in memory. Only computed when used or
Virtual View
accessed.
The data about the data. Describes elements such as
Metadata
columns, names, and data type.
Ordered collection of elements in parentheses. Tuple
% of table rows selected by a query Hit Ration
Reads blocks directly, without accessing an index. Table Scan
Reads index blocks sequentially in order to locate the
Index Scan
needed table blocks.
Database repeatedly splits the index in two until it finds a
Binary Search
match.
, WGU D426 V2 - 2026-2027 Comprehensive Frequently Tested Questions With Verified
Multiple Choice and Conceptual Actual 100% Correct Detailed Answers
Guaranteed Pass!!Current Update!!
Database object that maps one or more tables to a single
Tablespace
file.
Specifies tables, columns, and keys. Implements database
requirements in a specific database system. Also called a Logical Design
schema.
Specifies indexes, table structures, and partitions. Speci-
Physical Design
fies how tables are organized on storage media.
Components of a computer system and the relationships
Architecture
between components.
Interact directly with database users and administrators
and send queries to the query processor. Includes Con- Tools
nectors & APIs, Workbench, and utility programs.
Interprets queries. Compiles queries into low-level in-
structions for the storage engine. Creates a plan to modify
Query Processor
the database or retrieve data, and returns query results to
the application.
Link between tools and query processor Connection
Creates connections and manages communication be-
Connection Manager
tween tools and query parser.
Translates the query processor instructions into low-level
Storage Engine
file system commands that modify or retrieve data.
Accesses data on storage media. Data stored on storage
media and organized in files. Contains 3 types of data:
- User data (tables & indexes) - Log files (record of any
File System
changes) - Data dictionary (aka: catalog directory of ta-
bles, columns, keys, indexes in a relational database). One
row for each database object.
Stores reusable information in main memory. Cache Manager
, WGU D426 V2 - 2026-2027 Comprehensive Frequently Tested Questions With Verified
Multiple Choice and Conceptual Actual 100% Correct Detailed Answers
Guaranteed Pass!!Current Update!!
Retains data blocks from the file system for possible reuse. Butter Manager
Arranged in hierarchy Multi-tier architecture
Multi-tier consisting of web browsers and web servers
Web architecture
communicating over the internet.
A software layer that emulates a complete, independent
Virtual Machine
computing environment.
A database ottered as a PaaS cloud service. Cloud Database
A statement or proposition from which another statement
Premise
is inferred.
Multiple processors managed by a single operating sys-
tem instance.
Shared memory - share the same memory and storage
Parallel Computer
media.
Shared storage - share storage media only.
Shared nothing
Group of computers connected by LAN or WAN Node
Group of nodes connected by a LAN, managed by sep-
arate operating system instances. Similar to a parallel Cluster
computer.
Runs on a parallel computer or cluster Parallel Database
Runs on multiple computers connected by a WAN Distributed Database
Updates data on multiple nodes of a distributed database.
Two-phase commit (nodes receive notice of update, store
update in log, send confirmation, then receive commit). Distributed Transactions
Either all nodes or no nodes must be successfully updat-
ed.
Updates data on a single node of a distributed database.
Local Transaction
Databases that use this are called "eventually consistent".
