CompTIA CompTIA Certifications DS0-001 Questions & Answers

• Question 11:

  A new retail store employee needs to be able to authenticate to a database. Which of the following commands should a database administrator use for this task?

  A. INSERT USER

  B. ALLOW USER

  C. CREATE USER

  D. ALTER USER

  Correct Answer: C

  The command that the database administrator should use for this task is CREATE USER. The CREATE USER command is a SQL statement that creates a new user account in a database and assigns it a username and a password. The CREATE USER command also allows the database administrator to specify other options or attributes for the user account, such as default tablespace, quota, profile, role, etc. The CREATE USER command is the first step to enable a user to authenticate to a database. The other options are either invalid or not suitable for this task. For example, INSERT USER is not a valid SQL command; ALLOW USER is not a SQL command, but a keyword used in some database systems to grant permissions to users; ALTER USER is a SQL command that modifies an existing user account, but does not create a new one. References: CompTIA DataSys+ Course Outline, Domain 4.0 Data and Database Security, Objective 4.2 Given a scenario, implement security controls for databases.

• Question 12:

  A company is launching a proof-of-concept, cloud-based application. One of the requirements is to select a database engine that will allow administrators to perform quick and simple queries on unstructured data.Which of the following would bebestsuited for this task?

  A. MonogoDB

  B. MS SQL

  C. Oracle

  D. Graph database

  Correct Answer: A

  The best suited database engine for this task is MongoDB. MongoDB is a type of non-relational database that stores data as documents in JSON-like format. MongoDB allows administrators to perform quick and simple queries on unstructured data, such as text, images, videos, or social media posts, without requiring a predefined schema or complex joins. MongoDB also supports cloud-based deployment, scalability, and high availability. The other options are either relational databases that require a fixed schema and structure for data, or specialized databases that are designed for specific purposes, such as graph databases for storing and analyzing network data. References: CompTIA DataSys+ Course Outline, Domain 1.0 Database Fundamentals, Objective 1.1 Given a scenario, identify and apply database structure types.

• Question 13:

  A database administrator manages a database server that is running low on disk space. A lot of backup files are stored on the server's disks.

  Which of the following is thebestaction for the administrator to take?

  A. Move all the backup files to external disks.

  B. Delete all the backup files containing data that is rated as classified.

  C. Delete all the backup files that are not required by the backup retention policy.

  D. Delete all the backup files except for the most recent one.

  Correct Answer: C

  The best action for the administrator to take is to delete all the backup files that are not required by the backup retention policy. This will free up disk space on the server and also comply with the best practices for data backup and recovery. The backup retention policy defines how long the backup files should be kept and when they should be deleted or archived. The other options are either risky, inefficient, or impractical. For example, moving all the backup files to external disks would require additional hardware and time, deleting all the backup files containing data that is rated as classified would compromise data security and compliance, and deleting all the backup files except for the most recent one would limit the recovery options in case of a disaster. References: CompTIA DataSys+ Course Outline, Domain 5.0 Business Continuity, Objective 5.2 Given a scenario, implement backup and restoration of database management systems.

• Question 14:

  Which of the followingbestdescribes the category of SQL commands required to revoke access to database objects?

  A. DCL

  B. IDDL

  C. IDML

  D. TCL

  Correct Answer: A

  The category of SQL commands that is required to revoke access to database objects is DCL. DCL, or Data Control Language, is a subset of SQL commands that are used to control or manage the access or permissions of users or roles on a database. DCL includes commands such as GRANT and REVOKE. GRANT is a DCL command that is used to grant privileges or roles to users or roles on specific objects in a database, such as tables, views, procedures, etc. REVOKE is a DCL command that is used to revoke privileges or roles from users or roles on specific objects in a database. For example, the following statement uses the REVOKE command to revoke the SELECT privilege from user Alice on table employee: REVOKE SELECT ON employee FROM Alice;

  The other options are either different categories of SQL commands or not related to SQL commands at all. For example, IDDL is not a valid acronym or category of SQL commands; IDML is not a valid acronym or category of SQL commands; TCL, or Transaction Control Language, is a subset of SQL commands that are used to control or manage transactions on a database, such as committing or rolling back changes. References: CompTIA DataSys+ Course Outline, Domain 4.0 Data and Database Security, Objective 4.2 Given a scenario, implement security controls for databases.

• Question 15:

  Which of the following indexes stores records in a tabular format?

  A. Columnstore

  B. Non-clustered

  C. Unique

  D. Secondary

  Correct Answer: A

  The index that stores records in a tabular format is columnstore. A columnstore index is a type of index that stores and compresses data by columns rather than by rows. A columnstore index can improve the performance and efficiency of queries that perform aggregations, calculations, or analysis on large amounts of data, such as data warehouse or business intelligence applications. A columnstore index can also reduce the storage space required for data by applying various compression techniques, such as dictionary encoding, run-length encoding, bit packing, etc. The other options are either different types of indexes or not related to indexes at all. For example, a non-clustered index is a type of index that stores the values of one or more columns in a sorted order along with pointers to the corresponding rows in the table; a unique index is a type of index that enforces uniqueness on one or more columns in a table; a secondary index is an alternative term for a non-clustered index. References: CompTIA DataSys+ Course Outline, Domain 3.0 Database Management and Maintenance, Objective 3.1 Given a scenario, perform common database maintenance tasks.

• Question 16:

  A database professional is considering denormalizing a database. Which of the following documents should be used to analyze the database's structure?

  A. SOP

  B. Data dictionaries

  C. UML diaqrams

  D. ERD

  Correct Answer: D

  The document that should be used to analyze the database's structure is an ERD. An ERD, or Entity Relationship Diagram, is a graphical representation of the entities (tables), attributes (columns), and relationships (constraints) in a database. An ERD helps to visualize the structure and design of the database, as well as the dependencies and associations among the tables. An ERD can also help to evaluate the level of normalization of the database, which is a process that organizes data into tables and columns to reduce redundancy and improve consistency. Byusing an ERD, a database professional can consider denormalizing a database, which is a process that introduces some redundancy or duplication of data to improve performance or simplify queries. The other options are either different types of documents or not related to the database's structure. For example, an SOP, or Standard Operating Procedure, is a document that describes the steps and procedures for performing a specific task or operation; a data dictionary is a document that describes the metadata (information about data) of a database; a UML diagram is a graphical representation of a software system or its components using the Unified Modeling Language (UML). References: CompTIA DataSys+ Course Outline, Domain 2.0 Database Deployment, Objective 2.2 Given a scenario, create database objects using scripting and programming languages.

• Question 17:

  Which of the following computer services associates IP network addresses with text-based names in order to facilitate identification and connectivity?

  A. LDAP

  B. NTP

  C. DHCP

  D. IDNS

  Correct Answer: D

  The computer service that associates IP network addresses with text-based names in order to facilitate identification and connectivity is IDNS. IDNS, or Internet Domain Name System (DNS), is a service that translates domain names into IP addresses and vice versa. Domain names are human-readable names that identify websites or devices on the internet, such as www.comptia.org or www.google.com. IP addresses are numerical identifiers that locate websites or devices on the internet, such as 104.18.26.46 or 142.250.72.238. IDNS helps users to access websites or devices using domain names instead of IP addresses, which are easier to remember and type. IDNS also helps administrators to manage websites or devices using domain names instead of IP addresses, which are more flexible and scalable. The other options are either different computer services or not related to IP network addresses or text-based names at all. For example, LDAP, or Lightweight Directory Access Protocol, is a service that provides access to directory information such as users, groups, or devices on a network; NTP, or Network Time Protocol, is a service that synchronizes the clocks of computers or devices on a network; DHCP, or Dynamic Host Configuration Protocol, is a service that assigns IP addresses and other network configuration parameters to computers or devices on a network. References: CompTIA DataSys+ Course Outline, Domain 2.0 Database Deployment, Objective 2.1 Given a scenario, select an appropriate database deployment method.

• Question 18:

  A database administrator is conducting a stress test and providing feedback to a team that is developing an application that uses the Entity Framework. Which of the following explains the approach the administrator should use when conducting the stress test?

  A. Capture business logic, check the performance of codes, and report findings.

  B. Check the clustered and non-clustered indexes, and report findings.

  C. Review application tables and columns, and report findings.

  D. Write queries directly into the database and report findings.

  Correct Answer: A

  The approach that the administrator should use when conducting the stress test is to capture business logic, check the performance of codes, and report findings. This will help the administrator to evaluate how well the application handles high volumes of data and transactions, identify any bottlenecks or errors in the code, and provide feedback to the development team on how to improve the application's efficiency and reliability. The other options are either too narrow or too broad in scope, and do not address the specific needs of an application that uses the Entity Framework. References: CompTIA DataSys+ Course Outline, Domain 4.0 Data and Database Security, Objective 4.3 Given a scenario, monitor database performance and security.

• Question 19:

  Which of the following types of RAID, if configured with the same number and type of disks, would provide thebestwrite performance?

  A. RAID 3

  B. RAID 5

  C. RAID 6

  D. RAID 10

  Correct Answer: D

  The type of RAID that would provide the best write performance if configured with the same number and type of disks is RAID 10. RAID 10, or RAID 1+0, is a type of RAID that combines mirroring and striping techniques to provide both redundancy and performance. Mirroring means that data is duplicated across two or more disks to provide fault tolerance and data protection. Striping means that data is split into blocks and distributed across two or more disks to provide faster access and throughput. RAID 10 requires at least four disks and can tolerate the failure of up to half of the disks without losing data. RAID 10 provides the best write performance among the RAID types because it can write data in parallel to multiple disks without parity calculations or overhead. The other options are either different types of RAID or not related to RAID at all. For example, RAID 3 is a type of RAID that uses striping with a dedicated parity disk to provide redundancy and performance; RAID 5 is a type of RAID that uses striping with distributed parity to provide redundancy and performance; RAID 6 is a type ofRAID that uses striping with double distributed parity to provide extra redundancy and performance. References: CompTIA DataSys+ Course Outline, Domain 3.0 Database Management and Maintenance, Objective 3.1 Given a scenario, perform common database maintenance tasks.

• Question 20:

  Given the following customer table:

  

  Which of the following ORM snippets would return the ID, state, and country of all customers with the newest customers appearingfirst?

  

  A. Option A

  B. Option B

  C. Option C

  D. Option D

  Correct Answer: C

  The ORM snippet that would return the ID, state, and country of all customers with the newest customers appearing first is option C. This snippet uses the select method to specify the columns to be returned, the order method to sort the results by ID in descending order, and the all method to fetch all the records. The other options either have syntax errors, use incorrect methods, or do not sort the results correctly. References: CompTIA DataSys+ Course Outline, Domain 1.0 Database Fundamentals, Objective 1.2 Given a scenario, execute database tasks using scripting and programming languages.