WGU D426 V2 questions with verified answers
The relationship (within the relation) that describes how the value of one
attribute may be used to find the value of another attribute. Ans ✔✔-
Functional Dependency
An attribute that can be used to find the value of another attribute in the
relation. Ans ✔✔-Determinant
Value can be used to find the value of every other non-key attribute in
the table. Unique and minimal. Ans ✔✔-Candidate Key
Define & manage database structures Ans ✔✔-DDL
Adding, deleting, and modifying data - Manipulates data stored in a
database. Ans ✔✔-DML
Used to create user accounts, manage permissions and access. Ans ✔✔-
DCL
Includes CREATE, DROP, ALTER, TRUNCATE, RENAME Ans ✔✔-
DDL
A view created and stored on the database. Underlying data is changed
and also updated in this view. Uses memory space. Ans ✔✔-Materialized
View
,Not stored in memory. Only computed when used or accessed. Ans ✔✔-
Virtual View
The data about the data. Describes elements such as columns, names,
and data type. Ans ✔✔-Metadata
Ordered collection of elements in parentheses. Ans ✔✔-Tuple
% of table rows selected by a query Ans ✔✔-Hit Ration
Reads blocks directly, without accessing an index. Ans ✔✔-Table Scan
Reads index blocks sequentially in order to locate the needed table
blocks. Ans ✔✔-Index Scan
Database repeatedly splits the index in two until it finds a match. Ans
✔✔-Binary Search
Database object that maps one or more tables to a single file. Ans ✔✔-
Tablespace
Specifies tables, columns, and keys. Implements database requirements
in a specific database system. Also called a schema. Ans ✔✔-Logical
Design
, Specifies indexes, table structures, and partitions. Specifies how tables
are organized on storage media. Ans ✔✔-Physical Design
Components of a computer system and the relationships between
components. Ans ✔✔-Architecture
Interact directly with database users and administrators and send queries
to the query processor. Includes Connectors & APIs, Workbench, and
utility programs. Ans ✔✔-Tools
Interprets queries. Compiles queries into low-level instructions for the
storage engine. Creates a plan to modify the database or retrieve data,
and returns query results to the application. Ans ✔✔-Query Processor
Link between tools and query processor Ans ✔✔-Connection
Creates connections and manages communication between tools and
query parser. Ans ✔✔-Connection Manager
Translates the query processor instructions into low-level file system
commands that modify or retrieve data. Ans ✔✔-Storage Engine
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 changes) - Data dictionary (aka:
catalog directory of tables, columns, keys, indexes in a relational
database). One row for each database object. Ans ✔✔-File System
The relationship (within the relation) that describes how the value of one
attribute may be used to find the value of another attribute. Ans ✔✔-
Functional Dependency
An attribute that can be used to find the value of another attribute in the
relation. Ans ✔✔-Determinant
Value can be used to find the value of every other non-key attribute in
the table. Unique and minimal. Ans ✔✔-Candidate Key
Define & manage database structures Ans ✔✔-DDL
Adding, deleting, and modifying data - Manipulates data stored in a
database. Ans ✔✔-DML
Used to create user accounts, manage permissions and access. Ans ✔✔-
DCL
Includes CREATE, DROP, ALTER, TRUNCATE, RENAME Ans ✔✔-
DDL
A view created and stored on the database. Underlying data is changed
and also updated in this view. Uses memory space. Ans ✔✔-Materialized
View
,Not stored in memory. Only computed when used or accessed. Ans ✔✔-
Virtual View
The data about the data. Describes elements such as columns, names,
and data type. Ans ✔✔-Metadata
Ordered collection of elements in parentheses. Ans ✔✔-Tuple
% of table rows selected by a query Ans ✔✔-Hit Ration
Reads blocks directly, without accessing an index. Ans ✔✔-Table Scan
Reads index blocks sequentially in order to locate the needed table
blocks. Ans ✔✔-Index Scan
Database repeatedly splits the index in two until it finds a match. Ans
✔✔-Binary Search
Database object that maps one or more tables to a single file. Ans ✔✔-
Tablespace
Specifies tables, columns, and keys. Implements database requirements
in a specific database system. Also called a schema. Ans ✔✔-Logical
Design
, Specifies indexes, table structures, and partitions. Specifies how tables
are organized on storage media. Ans ✔✔-Physical Design
Components of a computer system and the relationships between
components. Ans ✔✔-Architecture
Interact directly with database users and administrators and send queries
to the query processor. Includes Connectors & APIs, Workbench, and
utility programs. Ans ✔✔-Tools
Interprets queries. Compiles queries into low-level instructions for the
storage engine. Creates a plan to modify the database or retrieve data,
and returns query results to the application. Ans ✔✔-Query Processor
Link between tools and query processor Ans ✔✔-Connection
Creates connections and manages communication between tools and
query parser. Ans ✔✔-Connection Manager
Translates the query processor instructions into low-level file system
commands that modify or retrieve data. Ans ✔✔-Storage Engine
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 changes) - Data dictionary (aka:
catalog directory of tables, columns, keys, indexes in a relational
database). One row for each database object. Ans ✔✔-File System
