CompTIA · Free Practice Questions · Last reviewed May 2026
30real exam-style questions organised by domain, each with the correct answer highlighted and a plain-English explanation of why it's right — and why the others are wrong.
A database administrator is planning to normalize a flat-file database containing customer orders. The administrator identifies that customer contact information is repeated for every order record. Which normalization form should the administrator implement to move this contact information to a separate table?
First Normal Form (1NF)
Second Normal Form (2NF)
2NF removes partial functional dependencies by separating data into distinct tables.
Boyce-Codd Normal Form (BCNF)
Third Normal Form (3NF)
A data architect is designing a schema for a high-concurrency e-commerce system. They decide to use a surrogate key instead of a natural key for the Orders table to ensure join performance and data integrity. What is the primary advantage of this design choice?
It reduces the storage size of the index compared to a string-based natural key
Integer-based surrogate keys are highly efficient for indexing and foreign key joins.
It prevents the insertion of duplicate records
It ensures that the database complies with ACID requirements
It automatically creates a clustered index on the table
A database developer is implementing a partitioning strategy for a large table containing historical financial records. The requirement is to allow for efficient archival of data older than five years. Which partitioning strategy should be chosen?
Range partitioning
Range partitioning is ideal for time-series data, allowing for efficient partition dropping or archiving.
Composite partitioning
List partitioning
Hash partitioning
Round-robin partitioning
During the pre-deployment phase, a team needs to estimate the hardware resources required for a new Oracle Database installation. Which tool should be used to simulate database workload and forecast resource consumption?
Automatic Workload Repository (AWR)
Oracle Database Replay
Database Replay allows for accurate capacity planning by replaying captured workloads on new hardware.
Oracle Enterprise Manager Performance Hub
SQL Tuning Advisor
You are deploying a database to a cloud environment and need to ensure that data at rest is encrypted according to organizational security policy. Which deployment configuration ensures transparent encryption of the database files?
Implementing Transparent Data Encryption (TDE)
TDE encrypts the database, log files, and backups at rest without requiring application code changes.
Applying column-level encryption
Using a Virtual Private Cloud (VPC) endpoint
Enabling SSL/TLS on the connection string
An organization is deploying a new SQL Server database. The storage administrator needs to ensure that the transaction logs are stored on a separate physical volume from the data files to improve performance and recoverability. Which configuration step accomplishes this?
Implementing a striped RAID 0 volume
Enabling FileStream on the target volume
Modifying the default file locations in SQL Server Management Studio (SSMS) Server Properties
Setting default file locations in instance properties ensures that data and log files are routed to different volumes during database creation.
Increasing the recovery model to Full
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Practice this domainA database administrator needs to store unstructured data that scales horizontally across multiple servers while maintaining high availability. Which database structure should be selected?
Relational (RDBMS)
NoSQL (Document Store)
NoSQL databases provide the flexibility for unstructured data and distributed horizontal scaling.
Network
Hierarchical
A user wants to add a new column to an existing table named 'Employees'. Which SQL statement should be executed?
MODIFY TABLE
UPDATE TABLE
CREATE COLUMN
ALTER TABLE
ALTER TABLE is the correct command to add a column.
To improve read performance on a table frequently queried by a specific column, which database object should be created?
Index
An index is specifically designed to accelerate data retrieval.
View
Stored Procedure
Trigger
A database administrator is investigating performance degradation during heavy concurrent write operations. Which isolation level provides the highest level of data consistency but the lowest concurrency?
Read Committed
Repeatable Read
Serializable
Serializable provides the highest consistency by preventing all concurrency-related anomalies.
Read Uncommitted
A developer needs to ensure that a 'Customer_ID' field in a 'Orders' table always references a valid ID in the 'Customers' table. Which constraint should be applied?
PRIMARY KEY
UNIQUE
CHECK
FOREIGN KEY
FOREIGN KEY enforces referential integrity between tables.
Which SQL command is used to permanently remove all rows from a table while keeping the table definition intact?
DELETE
DROP
REMOVE
TRUNCATE
TRUNCATE effectively clears all data in a table.
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Practice this domainTo comply with CCPA, an organization must track the 'Right to Know' requests. Which component of a Data Governance Framework is most relevant?
Data Ingestion Pipeline
Data Cataloging
Catalogs map data assets to owners and sensitivity levels.
Load Balancing
Data Compression
Which access control model should be implemented to ensure that a user can only access files based on their specific job role?
Discretionary Access Control (DAC)
Role-Based Access Control (RBAC)
RBAC is the standard for role-centric access management.
Mandatory Access Control (MAC)
Network Access Control (NAC)
An administrator needs to restrict access to a specific S3 bucket so that only the Finance team can view files. Which configuration is the most effective approach?
Configure an S3 Bucket Policy
Bucket policies allow for fine-grained resource-based access control.
Update the VPC Route Table
Enable Public Access Block
Enable S3 Versioning
An organization is migrating sensitive financial records to a cloud environment. Which security control ensures that only authorized applications can decrypt the data?
Database Replication
Cloud Hardware Security Module (Cloud HSM)
Cloud HSMs provide high-assurance storage for keys used by authorized applications.
Database Triggers
Shared Responsibility Model
A company subject to GDPR needs to ensure that user data is deleted upon request across all distributed nodes in a NoSQL cluster. Which process is most critical to demonstrate compliance?
Snapshotting
Database Sharding
Cache clearing
Automated Data Lineage and Lifecycle Tracking
Data lineage ensures the organization knows where all copies of PII reside.
A data analyst discovers that raw log files contain unmasked social security numbers. Which data governance practice should be implemented immediately to remediate the risk?
Dynamic Data Masking (DDM)
DDM obscures sensitive data from unauthorized users at the query layer.
Partitioning
Database Mirroring
Database Indexing
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Practice this domainA DBA is configuring an Always On Availability Group in SQL Server. To ensure that the secondary node can be used for read-only reporting tasks, which setting must be correctly configured in the Availability Group replica settings?
Readable Secondary
This setting enables the secondary replica to handle read-only workloads.
Automatic Failover
Synchronous Commit
Primary Role
A database administrator wants to move a heavily accessed table to a different physical storage tier to improve performance. In SQL Server, what is the best way to move the table data while retaining the clustered index?
Use the Move-Item cmdlet
Shrink the database
DROP and RECREATE index on a new filegroup
Moving the clustered index to a different filegroup physically moves the base table data.
Disable the index
A database administrator needs to ensure that a SQL Server transaction log does not grow uncontrollably during a high-volume ETL process. Which recovery model should be configured to allow for periodic log truncation while maintaining a balance between performance and recovery needs?
Differential
Bulk-Logged
Bulk-Logged recovery minimizes log space usage during bulk operations while still allowing for log backups.
Full
Simple
In PostgreSQL, you need to monitor the performance of your long-running queries. Which view is the most appropriate to inspect the query execution statistics for all active sessions?
pg_stat_database
pg_locks
pg_stat_user_tables
pg_stat_activity
This system view displays information about current backend processes and their active queries.
A DBA needs to implement transparent data encryption (TDE) for an entire database. Which component is required to protect the Database Encryption Key (DEK) in a SQL Server environment?
Active Directory group
Service Master Key
SSL/TLS certificate
Certificate
TDE uses a DEK, which must be protected by a certificate or an asymmetric key.
When planning a backup strategy, a company requires that the Recovery Point Objective (RPO) be set to 15 minutes. Which backup schedule meets this requirement?
Transaction Log Backups every 10 minutes
Backing up every 10 minutes ensures the data loss is limited to 10 minutes, satisfying the 15-minute RPO.
Daily Full Backups
Weekly Full and Daily Differential Backups
Hourly Transaction Log Backups
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Practice this domainAn analyst is using a CTE (Common Table Expression) to pre-aggregate sales data before performing a join. What is the primary benefit of using a CTE instead of a subquery in this scenario?
Better readability and recursive capability
CTEs provide logical structure and allow for recursive self-referencing queries.
Automatic indexing of the result set
Performance is always superior to subqueries
Lower memory consumption during execution
When joining two tables in SQL where you need to return all records from the left table even if there is no match in the right table, which JOIN type is appropriate?
LEFT JOIN
LEFT JOIN preserves all data from the primary table.
CROSS JOIN
INNER JOIN
FULL OUTER JOIN
Which SQL function is used to convert a NULL value in a query result into a default value, such as 0?
NVL
COALESCE
COALESCE is the standard ANSI SQL function for handling NULLs.
IFNULL
ISNULL
You are performing data transformation in Python using Pandas. You have a 'DataFrame' with missing values in the 'Revenue' column. Which method should be used to replace these missing values with the column mean?
replace()
fillna()
fillna() allows replacement of missing values with a specified statistic.
dropna()
interpolate()
map()
A data analyst is writing a SQL query to retrieve unique department names from the 'Employees' table. Which keyword should be utilized to ensure the results do not contain duplicate entries?
GROUP BY
DISTINCT
DISTINCT effectively filters out duplicate rows in a result set.
UNIQUE
FILTER
In Power BI, which visualization component is best suited to show the relationship between two numerical variables and identify potential trends or clusters?
Gauge Chart
Scatter Plot
Scatter plots effectively reveal relationships between two numerical dimensions.
Pie Chart
Clustered Column Chart
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Practice this domainThe DS0-001 exam has 200 questions and must be completed in 120 minutes. The passing score is 700/1000.
Multiple-choice and performance-based questions covering IT security, networking, and operations. Some questions are performance-based (PBQs), asking you to complete tasks in a simulated environment.
The exam covers 5 domains: Database Planning And Deployment, Database Structures And SQL, Data Governance And Security, Data Systems Management, Data Querying And Analysis. Questions are weighted by domain — higher-weight domains appear more on your actual exam.
No. These are original exam-style practice questions written against the official CompTIA DS0-001 exam objectives. They are not copied from the real exam. Courseiva focuses on genuine understanding, not memorisation of braindumps.
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