WGU - D426: Objective Assessment|A+ Graded
Questions with Complete Answers
Database Application
Software that helps business users interact with database systems.
Database Administrator
Responsible for securing the database system against unauthorized users. A database administrator
enforces procedures for user access and database system availability.
Authorization
Many database users should have limited access to specific tables, columns, or rows of a database.
Database systems authorize individual users to access specific data.
Rules
Database systems ensure data is consistent with structural and business rules.
Query Processor
Interprets queries, creates a plan to modify the database or retrieve data, and returns query results to
the application. Performs query optimization to ensure the most efficient instructions are executed on
the data.
Storage Manager
Translates the query processor instructions into low-level file-system commands that modify or
retrieve data. Database sizes range from megabytes to many terabytes, so the storage manager uses
indexes to quickly locate data.
Transaction Manager
Ensures transactions are properly executed. The transaction manager prevents conflicts between
concurrent transactions. The transaction manager also restores the database to a consistent state in
the event of a transaction or system failure.
Metadata
Data about the database, such as column names and the number of rows in each table.
Relational Database
Stores data in tables, columns, and rows, similar to a spreadsheet.
Relational Database
All _________ ________ systems support the SQL query language.
Relational Database
Relational systems are ideal for databases that require an accurate record of every transaction, such
as banking, airline reservation systems, and student records.
, MongoDB (NoSQL)
The newer non-relational systems are called NoSQL, for 'not only SQL', and are optimized for big data.
SQL Statements
INSERT inserts rows into a table.
SELECT retrieves data from a table.
UPDATE modifies data in a table.
DELETE deletes rows from a table.
CREATE TABLE (Statement)
A statement that creates a new table by specifying the table and column names. Each column is
assigned a data type that indicates the format of column values. Data types can be numeric, textual,
or complex.
Data Type
INT stores integer values.
DECIMAL stores fractional numeric values.
VARCHAR stores textual values.
DATE stores year, month, and day.
Database Design
Analysis
Logical design
Physical design
Analysis Phase, Conceptual Design, Entity-Relationship Modeling (Database Design)
This phase specifies database requirements without regard to a specific database system.
Requirements are represented as entities, relationships, and attributes. An entity is a person, place,
activity, or thing. A relationship is a link between entities, and an attribute is a descriptive property of
an entity.
Logical Design (Database Design)
This phase implements database requirements in a specific database system. For relational database
systems, _________ design converts entities, relationships, and attributes into tables, keys, and
columns.
Physical Design
Specifies indexes, table structures, and partitions. This phase adds indexes and specifies how tables
are organized on storage media. Affects query processing speed but never affects the query result.
Data Independence
Allows database designers to tune query performance without changes to application programs.
Application Programming Interface (API)
To simplify the use of SQL with a general-purpose language, database programs typically use an
____________ _____________ _______________.
Questions with Complete Answers
Database Application
Software that helps business users interact with database systems.
Database Administrator
Responsible for securing the database system against unauthorized users. A database administrator
enforces procedures for user access and database system availability.
Authorization
Many database users should have limited access to specific tables, columns, or rows of a database.
Database systems authorize individual users to access specific data.
Rules
Database systems ensure data is consistent with structural and business rules.
Query Processor
Interprets queries, creates a plan to modify the database or retrieve data, and returns query results to
the application. Performs query optimization to ensure the most efficient instructions are executed on
the data.
Storage Manager
Translates the query processor instructions into low-level file-system commands that modify or
retrieve data. Database sizes range from megabytes to many terabytes, so the storage manager uses
indexes to quickly locate data.
Transaction Manager
Ensures transactions are properly executed. The transaction manager prevents conflicts between
concurrent transactions. The transaction manager also restores the database to a consistent state in
the event of a transaction or system failure.
Metadata
Data about the database, such as column names and the number of rows in each table.
Relational Database
Stores data in tables, columns, and rows, similar to a spreadsheet.
Relational Database
All _________ ________ systems support the SQL query language.
Relational Database
Relational systems are ideal for databases that require an accurate record of every transaction, such
as banking, airline reservation systems, and student records.
, MongoDB (NoSQL)
The newer non-relational systems are called NoSQL, for 'not only SQL', and are optimized for big data.
SQL Statements
INSERT inserts rows into a table.
SELECT retrieves data from a table.
UPDATE modifies data in a table.
DELETE deletes rows from a table.
CREATE TABLE (Statement)
A statement that creates a new table by specifying the table and column names. Each column is
assigned a data type that indicates the format of column values. Data types can be numeric, textual,
or complex.
Data Type
INT stores integer values.
DECIMAL stores fractional numeric values.
VARCHAR stores textual values.
DATE stores year, month, and day.
Database Design
Analysis
Logical design
Physical design
Analysis Phase, Conceptual Design, Entity-Relationship Modeling (Database Design)
This phase specifies database requirements without regard to a specific database system.
Requirements are represented as entities, relationships, and attributes. An entity is a person, place,
activity, or thing. A relationship is a link between entities, and an attribute is a descriptive property of
an entity.
Logical Design (Database Design)
This phase implements database requirements in a specific database system. For relational database
systems, _________ design converts entities, relationships, and attributes into tables, keys, and
columns.
Physical Design
Specifies indexes, table structures, and partitions. This phase adds indexes and specifies how tables
are organized on storage media. Affects query processing speed but never affects the query result.
Data Independence
Allows database designers to tune query performance without changes to application programs.
Application Programming Interface (API)
To simplify the use of SQL with a general-purpose language, database programs typically use an
____________ _____________ _______________.
