FC0-U71 Practice Test 34 — 15 Questions

Question 1

An e-commerce application experiences a data anomaly where an order is partially recorded: the order header is saved but some order line items are missing due to a system crash. Which property of database transactions is violated?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Atomicity. Atomicity ensures that a transaction is treated as a single, indivisible unit of work: either all operations (e.g., saving the order header and all line items) complete successfully, or none are applied. In this scenario, the system crash caused a partial write, leaving the order header committed while line items were lost, which directly violates atomicity. The database should have rolled back the entire transaction upon crash recovery, preventing the partial state.

Answer

Consistency

Answer

Isolation

Answer

Durability

Question 2

Which THREE of the following are common file extensions for image files?

Accepted Answer

.png. The .png (Portable Network Graphics) extension is a common image file format that uses lossless compression, supporting transparency and a wide color palette. It is widely used for web graphics and images requiring high quality without compression artifacts.

Answer

.mp3

Answer

.xlsx

Question 3

A web application uses a JavaScript function to validate user input on a registration form. The function checks that the password is at least 8 characters long and contains a number. When a user submits the form with a password "abc123", the validation passes even though the password has only 6 characters. The developer examines the code and finds that the function uses the condition: if (password.length >= 8 || /\d/.test(password)). Which logical error is causing this bug?

Accepted Answer

The condition uses OR instead of AND.. The condition uses OR (||) instead of AND (&&), so the validation passes if either condition is true. "abc123" has a number, so it passes. The regular expression is correct, length check is appropriate, and the function is called.

Answer

The function is not called.

Answer

The regular expression is incorrect.

Answer

The length check is incorrect because it uses >= instead of >.

Question 4

Which TWO of the following are examples of database management systems (DBMS)?

Accepted Answer

Microsoft SQL Server. Microsoft SQL Server is a relational database management system (RDBMS) developed by Microsoft. It uses Structured Query Language (SQL) to store, retrieve, and manage data in a structured format, making it a core example of a DBMS.

Answer

Python

Answer

HTML

Answer

Linux

Question 5

Refer to the exhibit. A database administrator executes the following query: SELECT COUNT(*) FROM employees WHERE department_id = 10; What is the result?

Accepted Answer

2. The query `SELECT COUNT(*) FROM employees WHERE department_id = 10;` counts all rows in the `employees` table where the `department_id` column equals 10. According to the exhibit (not shown here but implied), there are exactly two employees in department 10, so the result is 2.

Answer

3

Answer

0

Answer

1

Question 6

A junior developer is tasked with creating a function that checks whether a number is even or odd. The developer writes the following pseudocode: FUNCTION isEven(number) IF number % 2 == 0 THEN RETURN true ELSE RETURN false. The developer then realizes they need to handle non-integer input. Which of the following should the developer add to improve the robustness of this function?

Accepted Answer

Add input validation to check if the number is an integer.. Adding input validation to check if the number is an integer ensures the modulus operation works correctly. A parameter for number type is not standard. Changing the operator would break the logic. Deleting and using a library is overkill.

Answer

Delete the function and use a built-in library instead.

Answer

Change the modulus operator to a division operator.

Answer

Add a parameter for the number type.

Question 7

A database designer wants to avoid duplicate data across tables and ensure each table stores information about a single entity. Which process should the designer apply?

Accepted Answer

Normalization. Normalization is the process of organizing data in a database to reduce redundancy and dependency by dividing large tables into smaller, related tables and defining relationships between them. This ensures each table stores information about a single entity and avoids duplicate data across tables, aligning with the designer's goal.

Answer

Indexing

Answer

Transaction isolation

Answer

Backup and recovery

Question 8

A database administrator notices that a transaction that updates two tables is failing halfway, leaving data inconsistent. Which property of ACID ensures that the database returns to its original state if the transaction fails?

Accepted Answer

Atomicity. Atomicity (option D) ensures that a transaction is treated as a single, indivisible unit of work. If any part of the transaction fails (e.g., updating the second table), the entire transaction is rolled back, and the database returns to its original state before the transaction began. This prevents partial updates that would leave data inconsistent.

Answer

Consistency

Answer

Durability

Answer

Isolation

Question 9

A user wants to open a PDF file but receives an error that no application is associated. Which action should the user take?

Accepted Answer

Install a PDF reader. The error 'no application is associated' means the operating system lacks a default program capable of handling the PDF file format. Installing a PDF reader, such as Adobe Acrobat Reader or a web browser with built-in PDF support, registers the necessary file association and allows the file to open correctly.

Answer

Update device drivers

Answer

Rename the file to .docx

Answer

Restart the computer

Question 10

Which file extension is typically associated with a compressed archive?

Accepted Answer

.zip. The .zip file extension is the standard for compressed archives, using algorithms like DEFLATE (RFC 1951) to reduce file size and bundle multiple files into a single container. This makes it the correct answer for identifying a compressed archive format.

Answer

.pdf

Answer

.exe

Answer

.docx

Question 11

A user runs the query: SELECT * FROM Employees WHERE Department = 'Sales' AND Salary > 50000; but no rows are returned. The Department column contains 'Sales ' with a trailing space. What is the most likely cause?

Accepted Answer

The data has trailing spaces causing no match. The query uses an exact string comparison with 'Sales', but the stored data contains 'Sales ' (with a trailing space). In SQL, string comparisons are character-by-character, so the trailing space causes the equality check to fail, resulting in zero rows returned. This is a common data quality issue where invisible whitespace prevents matches.

Answer

The AND operator is incorrect

Answer

The column name is misspelled

Answer

Salary is stored as text

Question 12

Which TWO of the following are examples of high-level programming languages? (Select TWO).

Accepted Answer

Python. Python and Java are both high-level programming languages because they provide strong abstraction from the computer's hardware, using human-readable syntax and automatic memory management. Python is interpreted and dynamically typed, while Java is compiled to bytecode and statically typed, but both allow developers to write code without managing registers or memory addresses directly.

Answer

Machine code

Answer

Assembly

Answer

Binary

Question 13

Refer to the exhibit. A database administrator executes the DELETE statement, and it reports success. However, a subsequent SELECT still shows the row. Which is the most likely explanation?

Accepted Answer

The command was not committed.. In SQL databases, a DELETE statement removes rows from a table only when the transaction is committed. If the database is using implicit transactions or the user has not issued a COMMIT command, the deletion is held in a pending transaction and remains visible to other sessions (or even the same session if read consistency is applied). The reported 'success' indicates the statement executed without error, but without a commit, the changes are not made permanent, so a subsequent SELECT still shows the row.

Answer

The table is locked by another user.

Answer

The WHERE clause used the wrong value.

Answer

The user lacks DELETE privilege.

Question 14

Which three of the following are recommended practices for securing a home wireless network? (Choose three.)

Accepted Answer

Disable SSID broadcast. Disabling SSID broadcast makes the network name invisible in client scans, reducing casual discovery. However, it is a weak security measure because attackers can still detect the SSID using packet sniffing tools like Wireshark or airodump-ng when a client connects. It should be used as a minor deterrent, not a primary security control.

Answer

Enable MAC address filtering

Answer

Use the default router password

Question 15

Given the following pseudocode that calculates the average of a list of numbers, which error will occur?

SET total = 0
SET count = 0
FOR EACH number IN list
   total = total + number
   count = count + 1
ENDFOR
SET average = total / count
OUTPUT average

Accepted Answer

Runtime error. The pseudocode computes an average by dividing `total` by `count`. If the list is empty, `count` remains 0, and division by zero is a runtime error. This error occurs during execution, not during compilation or syntax checking, and is not a logic error because the code is logically correct for non-empty lists.

Answer

Compile-time error

Answer

Logic error

Answer

Syntax error