Database Administrator practice questions with answers

Updated 17 September 2026 · 2 min read

These questions cover the ground a database administrator works in: SQL and schema design, storage and hardware, Linux, and the security that sits around the data. Read each one as though the database in question were in production and someone were waiting. Decide, then check the explanation against your reasoning.

How this guide was made

Written for this site with AI assistance, then checked automatically before publishing. The topic table, sample questions, worked examples and study plan are generated from this site’s question bank: each worked example is recalculated by separate code, and each sample answer says where it came from.

The guide deliberately states no salaries, grades, pass marks or exam dates. Those change, and they could not be checked here, so take them from the advert itself.

This site is independent and is not affiliated with MIFOTRA or any employer.

Practice questions

What is a common method for securing user passwords?
1. Writing them down on paper
2. Sharing them openly
3. Using password hashing
4. Storing them in plain text
Show the answer
C. Using password hashing
Passwords are stored as salted hashes so the original value cannot be recovered from a database breach.
Real past-paper question; answer cross-checked against the original session. Open this question
An employee receives an SMS on their corporate phone stating their multi-factor authentication app needs a critical update, including a link to download an APK. What type of attack is occurring?
1. Vishing
2. Smishing
3. Pretexting
4. Whaling
Show the answer
B. Smishing
Smishing uses SMS text messages to deliver malicious links or social engineering lures. Vishing uses voice, while pretexting is the broader creation of a fabricated scenario.
Original practice question, written against published exam objectives. Open this question
Which file system is commonly used on Windows operating system?
1. HFS+
2. APFS
3. NTFS
4. EXT4
Show the answer
C. NTFS
NTFS is the standard Windows file system. EXT4 belongs to Linux; APFS and HFS+ are Apple file systems.
Real past-paper question; answer cross-checked against the original session. Open this question
A user is trying to install an unverified application. A prompt appears asking for administrator credentials to allow the installation. What Windows security feature is triggering this prompt?
1. SmartScreen
2. BitLocker
3. UAC (User Account Control)
4. Windows Defender Firewall
Show the answer
C. UAC (User Account Control)
UAC helps prevent unauthorized changes to the operating system by prompting for elevation or credentials when administrative tasks are attempted.
Original practice question, written against published exam objectives. Open this question
What is the primary benefit of using cloud storage services?
1. Remote access to files
2. Higher local storage capacity
3. Improved graphics performance
4. Faster processing speed
Show the answer
A. Remote access to files
Cloud storage makes files reachable from any location and device. It does not change local processing or graphics performance.
Real past-paper question; answer cross-checked against the original session. Open this question
An attacker leaves several USB drives labeled "Q3 Layoffs & Bonuses" in the company parking lot, hoping curious employees will plug them into corporate workstations. This technique is called...
1. Baiting
2. Dumpster diving
3. Watering hole
4. Pretexting
Show the answer
A. Baiting
Baiting relies on curiosity or greed, offering something enticing (like a USB drive with an interesting label) to trick the victim into compromising their system.
Original practice question, written against published exam objectives. Open this question
A contractor holding a large box of networking equipment waits by the secure datacenter door until an authorized employee scans their badge and opens it, then follows them inside. This is known as...
1. Baiting
2. Shoulder surfing
3. Tailgating
4. Piggybacking
Show the answer
C. Tailgating
Tailgating is following an authorized user into a restricted area without consent or proper authentication. Piggybacking implies the authorized user consented.
Original practice question, written against published exam objectives. Open this question
An administrator needs to enforce password complexity rules across all computers in a domain. Which Windows tool should they use?
1. Group Policy
2. Task Manager
3. Registry Editor
4. Device Manager
Show the answer
A. Group Policy
Group Policy allows administrators to manage and enforce configurations, security policies, and software installations across a network.
Original practice question, written against published exam objectives. Open this question

Ask what the data would actually do

For any query question, imagine a small table and run the query in your head, row by row. For any design question, ask what happens when the data grows, when two users write at once, and when something has to be deleted. Databases punish designs that only work while the table is small.

Sort your mistakes by area

Record each wrong answer as SQL, design, performance, transactions, backup, security or availability. Most candidates find that one or two areas account for most of their losses, and those are the ones worth a weekend.

Do not trust a query you have not run

When a question shows SQL, resist the pull of the option that merely looks tidy. Trace the rows, check whether a null could appear, and confirm the grouping matches the columns selected. Candidates lose more marks to plausible-looking SQL than to difficult concepts.

After this set

The worked calculations below cover storage capacity, transfer times and search efficiency, which come up when sizing servers and judging whether a query will scale. More questions from the full bank follow them.

Two calculations to try

Try each one on paper first. Every figure is generated and then recalculated by separate code before it is published.

Usable space in RAID 6
A server has 6 × 2 TB disks in RAID 6. How much usable capacity is there, and what failure can it survive?
Show the working
1. RAID 6 spends two disks’ worth on dual parity: (n − 2) × size.
2. Usable = 8 TB
3. It survives two disk failures.
Answer: 8 TB; survives two disk failures
Worst-case comparisons in a binary search
A sorted array holds 1000000 records. In the worst case, how many comparisons does a binary search need, and how many would a linear search need?
Show the working
1. Each binary-search comparison halves what is left, so the worst case is ⌊log₂ n⌋ + 1 comparisons.
2. log₂(1000000) ≈ 19.93, so ⌊19.93⌋ + 1 = 20
3. A linear search may have to check every record: 1000000 comparisons. That gap is what O(log n) versus O(n) means in practice.
Answer: 20 comparisons (binary) versus 1000000 (linear)

Common questions

Why are storage and Linux questions in a database set?

Databases run on storage and, more often than not, on Linux. Administrators size disks, watch space, tune file systems and read logs, so tests cover the platform as well as the engine.

Should I practise writing SQL by hand?

Yes. Written tests ask for queries on paper, and writing them without autocomplete exposes gaps that a code editor hides.