D426 WGU (MASTER) Practice Exam
Questions with Verified Correct Answers
Database application
A program that lets business users interact with database systems.
Database administrator (DBA)
Secures the DB, manages access, and enforces availability procedures.
Authorization
Limits user access to specific tables, columns, or rows.
Business rules
Rules that keep data consistent with structural and policy constraints.
Query processor
Parses queries, optimizes plans, and returns results.
Storage manager
Executes low-level file operations and uses indexes to locate data.
Transaction manager
Ensures ACID execution and recovery from failures.
CRUD: INSERT
Adds new rows to a table.
CRUD: SELECT
Retrieves data from a table.
CRUD: UPDATE
Modifies existing rows in a table.
CRUD: DELETE
, Removes rows from a table.
CREATE TABLE
Defines a new table with columns and data types.
DROP TABLE
Deletes a table and all its rows.
ALTER TABLE
Adds, drops, or modifies columns or constraints of a table.
INT
Data type for integers.
DECIMAL(M,D)
Data type for fixed-precision numbers.
VARCHAR(N)
Data type for variable-length text up to N chars.
DATE
Data type for year, month, day.
Tuple
Ordered list of values; order matters.
Table
Set of rows with a fixed tuple of columns; rows have no inherent order.
Row (record, tuple)
Unordered tuple of values matching the table's columns.
Column (field, attribute)
Named data element with a data type.
SQL sublanguages
DDL, DQL, DML, DCL, DTL.
DDL
Questions with Verified Correct Answers
Database application
A program that lets business users interact with database systems.
Database administrator (DBA)
Secures the DB, manages access, and enforces availability procedures.
Authorization
Limits user access to specific tables, columns, or rows.
Business rules
Rules that keep data consistent with structural and policy constraints.
Query processor
Parses queries, optimizes plans, and returns results.
Storage manager
Executes low-level file operations and uses indexes to locate data.
Transaction manager
Ensures ACID execution and recovery from failures.
CRUD: INSERT
Adds new rows to a table.
CRUD: SELECT
Retrieves data from a table.
CRUD: UPDATE
Modifies existing rows in a table.
CRUD: DELETE
, Removes rows from a table.
CREATE TABLE
Defines a new table with columns and data types.
DROP TABLE
Deletes a table and all its rows.
ALTER TABLE
Adds, drops, or modifies columns or constraints of a table.
INT
Data type for integers.
DECIMAL(M,D)
Data type for fixed-precision numbers.
VARCHAR(N)
Data type for variable-length text up to N chars.
DATE
Data type for year, month, day.
Tuple
Ordered list of values; order matters.
Table
Set of rows with a fixed tuple of columns; rows have no inherent order.
Row (record, tuple)
Unordered tuple of values matching the table's columns.
Column (field, attribute)
Named data element with a data type.
SQL sublanguages
DDL, DQL, DML, DCL, DTL.
DDL
