WGU D426 Objective Assessment Exam 2025
1. If a database designer chooses a 15-byte character string as a primary key
instead of a 2-byte integer, what impact might this decision have on query
performance?
It will improve data integrity.
It will increase the size of the database.
It will simplify the database schema.
It may slow down query processing.
2. What is metadata in the context of databases?**
Integrated tables in a database
Summed, ordered, or averaged data
Data about data
Information derived from data
3. In the relational model, a column is __ _.
an unnamed tuple of values
a name and a data type
the result of an SQL statement
an unnamed set of values
4. Describe how data is organized in a relational database and how it
compares to a spreadsheet.
, Data in a relational database is stored in binary format, while
spreadsheets use text format.
Data in a relational database is stored in a single file, unlike a
spreadsheet which uses multiple sheets.
Data in a relational database is organized in a hierarchical structure,
unlike a spreadsheet which is flat.
Data in a relational database is organized in tables, columns, and
rows, similar to a spreadsheet where each table represents a
different entity and each row represents an instance of that entity.
5. Describe the significance of ensuring that non-key columns depend on the
whole primary key in a database table.
Ensuring that non-key columns depend on the whole primary key
prevents partial dependency, which helps maintain data integrity
and reduces redundancy.
It allows for more columns to be added without affecting the
primary key.
It ensures that all data is stored in a single table without
relationships.
It allows for faster retrieval of data without the need for
normalization.
6. Describe the characteristics of a heap table in the context of database
design.
A heap table is optimized for read operations.
A heap table organizes rows based on a specific index.
A heap table is a type of table where rows are stored in no
particular order.
, A heap table requires a primary key for row identification.
7. What is the definition of an attribute instance in database terminology?
An individual value
A table structure
A type of database
A collection of values
8. What is the primary role of the query processor in database management?
Manages user access and permissions.
Ensures data redundancy and integrity.
Interprets queries and returns query results to the application.
Stores data in a structured format.
9. With respect to transaction processing, any DBMS should be capable of
Transactions do not make the database inconsistent.
Parts of a transaction are not lost due to a failure.
Ensuring that transactions are free from interference from other
users.
All of the above.
10. The TRUNCATE TABLE...
checks if the table has primary key specified
deletes all rows from a table
delete the rest of the rows in a table
, deletes the table
11. What is the purpose of the CREATE TABLE statement in SQL?
To update the values in an existing table.
To delete an existing table from the database.
To create a new table by specifying the table and column names.
To retrieve data from a specified table.
12. In a table, what has a name and a datatype?
set
row
tuple
column
13. Describe the purpose of the '!=' operator in SQL and how it is used in
queries.
The '!=' operator is used to join two tables in a database.
The '!=' operator checks for equality between two values in SQL.
The '!=' operator assigns values to variables in SQL statements.
The '!=' operator is used to compare two values and return true if
they are not equal, allowing for conditional filtering in queries.
14. If a database administrator needs to quickly remove all records from a
large table without affecting the table structure or logging each deletion,
which SQL command should they use?
1. If a database designer chooses a 15-byte character string as a primary key
instead of a 2-byte integer, what impact might this decision have on query
performance?
It will improve data integrity.
It will increase the size of the database.
It will simplify the database schema.
It may slow down query processing.
2. What is metadata in the context of databases?**
Integrated tables in a database
Summed, ordered, or averaged data
Data about data
Information derived from data
3. In the relational model, a column is __ _.
an unnamed tuple of values
a name and a data type
the result of an SQL statement
an unnamed set of values
4. Describe how data is organized in a relational database and how it
compares to a spreadsheet.
, Data in a relational database is stored in binary format, while
spreadsheets use text format.
Data in a relational database is stored in a single file, unlike a
spreadsheet which uses multiple sheets.
Data in a relational database is organized in a hierarchical structure,
unlike a spreadsheet which is flat.
Data in a relational database is organized in tables, columns, and
rows, similar to a spreadsheet where each table represents a
different entity and each row represents an instance of that entity.
5. Describe the significance of ensuring that non-key columns depend on the
whole primary key in a database table.
Ensuring that non-key columns depend on the whole primary key
prevents partial dependency, which helps maintain data integrity
and reduces redundancy.
It allows for more columns to be added without affecting the
primary key.
It ensures that all data is stored in a single table without
relationships.
It allows for faster retrieval of data without the need for
normalization.
6. Describe the characteristics of a heap table in the context of database
design.
A heap table is optimized for read operations.
A heap table organizes rows based on a specific index.
A heap table is a type of table where rows are stored in no
particular order.
, A heap table requires a primary key for row identification.
7. What is the definition of an attribute instance in database terminology?
An individual value
A table structure
A type of database
A collection of values
8. What is the primary role of the query processor in database management?
Manages user access and permissions.
Ensures data redundancy and integrity.
Interprets queries and returns query results to the application.
Stores data in a structured format.
9. With respect to transaction processing, any DBMS should be capable of
Transactions do not make the database inconsistent.
Parts of a transaction are not lost due to a failure.
Ensuring that transactions are free from interference from other
users.
All of the above.
10. The TRUNCATE TABLE...
checks if the table has primary key specified
deletes all rows from a table
delete the rest of the rows in a table
, deletes the table
11. What is the purpose of the CREATE TABLE statement in SQL?
To update the values in an existing table.
To delete an existing table from the database.
To create a new table by specifying the table and column names.
To retrieve data from a specified table.
12. In a table, what has a name and a datatype?
set
row
tuple
column
13. Describe the purpose of the '!=' operator in SQL and how it is used in
queries.
The '!=' operator is used to join two tables in a database.
The '!=' operator checks for equality between two values in SQL.
The '!=' operator assigns values to variables in SQL statements.
The '!=' operator is used to compare two values and return true if
they are not equal, allowing for conditional filtering in queries.
14. If a database administrator needs to quickly remove all records from a
large table without affecting the table structure or logging each deletion,
which SQL command should they use?
