CompTIA DS0-001 Online Practice Questions and Exam Preparation

CompTIA DS0-001 Online Questions & Answers

• Question 11:

  A developer is designing a table that does not have repeated values. Which of the following indexes should the developer use to prevent duplicate values from being inserted?

  A. Unique
  B. Single column
  C. Implicit
  D. Composite
  A. Unique

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  Explanation/Reference:

  The index that the developer should use to prevent duplicate values from being inserted is unique. A unique index is a type of index that enforces the uniqueness of the values in one or more columns of a table. A unique index ensures that no two rows in the table have the same value or combination of values in the indexed columns. A unique index helps to maintain data integrity and avoid data duplication or inconsistency. The other options are either not related or not effective for this purpose. For example, a single column index is a type of index that involves only one column of a table, but it does not prevent duplicate values unless it is also unique; an implicit index is a type of index that is automatically created by the database system when a constraint or a primary key is defined on a column or columns of a table, but it does not prevent duplicate values unless it is also unique; a composite index is a type of index that involves two or more columns of a table, but it does not prevent duplicate values unless it is also unique. References: CompTIA DataSys+ Course Outline, Domain 1.0 Database Fundamentals, Objective 1.2 Given a scenario, execute database tasks using scripting and programming languages.

• Question 12:

  Which of the following cloud delivery models provides users with thehighestlevel of flexibility regarding resource provisioning and administration?

  A. DBaaS
  B. IaaS
  C. SaaS
  D. PaaS
  B. IaaS

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  Explanation/Reference:

  The cloud delivery model that provides users with the highest level of flexibility regarding resource provisioning and administration is IaaS. IaaS, or Infrastructure as a Service, is a cloud delivery model that provides users with access to virtualized computing resources, such as servers, storage, network, and operating systems, over the internet. Users can provision, configure, and manage these resources according to their needs and preferences, without having to worry about the maintenance or security of the physical infrastructure. IaaS offers users the most control and customization over their cloud environment, as well as the ability to scale up or down as needed. The other options are either different cloud delivery models or not related to cloud computing at all. For example, DBaaS, or Database as a Service, is a cloud delivery model that provides users with access to database management systems and tools over the internet; SaaS, or Software as a Service, is a cloud delivery model that provides users with access to software applications and services over the internet; PaaS, or Platform as a Service, is a cloud delivery model that provides users with access to development platforms and tools over the internet. References: CompTIA DataSys+ Course Outline, Domain 2.0 Database Deployment, Objective 2.1 Given a scenario, select an appropriate database deployment method.

• Question 13:

  A database administrator needs to ensure database backups are occurring on a daily basis and at scheduled times. Which of the following actions should the administrator take?

  A. Query the database to observe entries.
  B. Check the database schema.
  C. Review the backup media.
  D. Review the server logs for entries.
  D. Review the server logs for entries.

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  Explanation/Reference:

  The action that the administrator should take is to review the server logs for entries. Server logs are files that record the events and activities that occur on a server, such as database backups, errors, warnings, or failures. By reviewing the server logs, the administrator can verify that the database backups are occurring on a daily basis and at scheduled times, and also identify any issues or anomalies that may affect the backup process or the backup quality. The other options are either not relevant or not sufficient for this task. For example, querying the database to observe entries may not show the backup status or frequency, checking the database schema may not reflect the backup schedule or policy, and reviewing the backup media may not indicate the backup time or duration. 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:

  A database administrator needs to ensure that a newly installed corporate business intelligence application can access the company's transactional data. Which of the following tasks should the administrator performfirst?

  A. Create a new service account exclusively for the business intelligence application.
  B. Build a separate data warehouse customized to the business intelligence application's specifications.
  C. Set up a nightly FTP data transfer from the database server to the business intelligence application server.
  D. Send the business intelligence administrator the approved TNS names file to configure the data mapping.
  E. Open a new port on the database server exclusively for the business intelligence application.
  A. Create a new service account exclusively for the business intelligence application.

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  Explanation/Reference:

  The first task that the administrator should perform is to create a new service account exclusively for the business intelligence application. This will ensure that the application has the appropriate permissions and credentials to access the company's transactional data. The other options are either unnecessary, inefficient, or insecure. For example, building a separate data warehouse would require additional resources and time, setting up a nightly FTP data transfer would expose the data to potential breaches, sending the TNS names file would not guarantee that the application can connect to the database, and opening a new port on the database server would create a vulnerability for attackers. References: CompTIA DataSys+ Course Outline, Domain 2.0 Database Deployment, Objective 2.1 Given a scenario, install and configure database software and tools.

• Question 15:

  A server administrator wants to analyze a database server's disk throughput. Which of the following should the administrator measure?

  A. RPfvl
  B. Latency
  C. IOPS
  D. Reads
  C. IOPS

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  Explanation/Reference:

  The factor that the administrator should measure to analyze a database server's disk throughput is IOPS. IOPS, or Input/Output Operations Per Second, is a metric that measures the number of read and write operations that a disk can perform in one second. IOPS indicates the performance or speed of a disk and how well it can handle multiple requests or transactions. Higher IOPS means higher disk throughput and lower latency. IOPS can be affected by various factors, such as disk type, size, speed, cache, RAID level, etc. The other options are either not related or not sufficient for this purpose. For example, RPfvl is not a valid acronym or metric; latency is the time delay between a request and a response; reads are the number of read operations performed by a disk. References: CompTIA DataSys+ Course Outline, Domain 3.0 Database Management and Maintenance, Objective 3.2 Given a scenario, monitor database performance.

• Question 16:

  Which of the following NFs is considered themostpreferable for relational database design?

  A. 1 NF
  B. 3 NF
  C. 4 NF
  D. 2NF
  B. 3 NF

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  Explanation/Reference:

  The NF (normal form) that is considered the most preferable for relational database design is 3 NF. 3 NF, or Third Normal Form, is a level of normalization that organizes data into tables and columns to reduce redundancy and improve consistency. Normalization is a process that applies a set of rules or criteria to eliminate or minimize the anomalies or problems that may arise from inserting, updating, or deleting data in a database. 3 NF is achieved when a table satisfies the following conditions: - It is in 2 NF (Second Normal Form), which means that every non-key column depends on the whole primary key and not on any subset of it - It has no transitive dependencies, which means that every non-key column depends directly on the primary key and not on any other non- key column 3 NF is considered the most preferable for relational database design because it ensures that each table has only one purpose or theme and that each column has only one value or meaning. This helps avoid data duplication, inconsistency, and update anomalies. The other options are either lower or higher levels of normalization that are either less preferable or less practical for relational database design. For example, 1 NF (First Normal Form) is the lowest level of normalization that requires each column to have atomic values and each row to have a unique identifier; 4 NF (Fourth Normal Form) is a higher level of normalization that requires each table to have no multi-valued dependencies, which means that there are no columns that can have more than one value for the same primary key value; 2 NF (Second Normal Form) is an intermediate level of normalization that requires each non-key column to depend on the whole primary key and not on any subset of it. References: CompTIA DataSys+ Course Outline, Domain 1.0 Database Fundamentals, Objective 1.2 Given a scenario, execute database tasks using scripting and programming languages.

• Question 17:

  A business analyst is using a client table and an invoice table to create a database view that shows clients who have not made purchases yet. Which of the following joins ismostappropriate for the analyst to use to create this database view?

  A. INNER JOIN ON Client.Key = Invoice.Key
  B. RIGHT JOIN ON Client.Key = Invoice.Key WHERE BY Client.Key ISNOLL
  C. LEFT JOIN ON Client.Key = Invoice.Key
  D. LEFT JOIN ON Client.Key = Invoice.Key WHEREBY Invoice.Key ISNOLL
  D. LEFT JOIN ON Client.Key = Invoice.Key WHEREBY Invoice.Key ISNOLL

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  Explanation/Reference:

  The join that is most appropriate for the analyst to use to create this database view is option D. This join uses the LEFT JOIN clause to combine the client table and the invoice table based on the matching values in the Key column. The WHERE clause filters out the rows where the Invoice.Key column is not null, meaning that the client has made a purchase. The result is a view that shows only the clients who have not made any purchases yet. The other options either do not produce the desired result or have syntax errors. For example, option A would show only the clients who have made purchases, option B would show only the invoices that do not have a matching client, and option C would show all the clients regardless of their purchase status. References: CompTIA DataSys+ Course Outline, Domain 1.0 Database Fundamentals, Objective 1.2 Given a scenario, execute database tasks using scripting and programming languages.

• Question 18:

  Which of the following NoSQL database typesbestcategorizes MongoDB?

  A. Document
  B. Column-oriented
  C. Graph
  D. Key-value stores
  A. Document

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  Explanation/Reference:

  The NoSQL database type that best categorizes MongoDB is document. Document databases are databases that store and manage data as documents, which are collections of fields and values in formats such as JSON (JavaScript Object Notation) or XML (Extensible Markup Language). Document databases do not use any schema or structure to organize data, but rather use identifiers or indexes to enable flexible and dynamic access to data based on fields or values. Document databases are suitable for storing large amounts of complex or unstructured data that have variable attributes or nested structures. MongoDB is an example of a document database that uses JSON-like documents to store and query data. The other options are either different types of NoSQL databases or not related to NoSQL databases at all. For example, column-oriented databases are databases that store and manage data as columns rather than rows; graph databases are databases that store and manage data as nodes and edges that represent entities and relationships; key-value stores are databases that store and manage data as pairs of keys and values. References: CompTIA DataSys+ Course Outline, Domain 1.0 Database Fundamentals, Objective 1.1 Given a scenario, identify common database types.

• Question 19:

  Which of the following have data manipulation and procedural scripting power? (Choose two.)

  A. PQL
  B. PL/SQL
  C. Advanced
  D. SQL
  E. SQL
  F. T-SQL
  B. PL/SQL
  F. T-SQL

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  Explanation/Reference:

  The two options that have data manipulation and procedural scripting power are PL/SQL and T-SQL. PL/SQL, or Procedural Language/Structured Query Language, is an extension of SQL that adds procedural features to SQL for Oracle databases. PL/SQL allows users to create and execute stored procedures, functions, triggers, packages, etc., using variables, loops, conditions, exceptions, etc., in addition to SQL commands. PL/SQL helps improve the performance, functionality, modularity, and security of SQL queries and applications. T-SQL, or Transact-SQL, is an extension of SQL that adds procedural features to SQL for Microsoft SQL Server databases. T-SQL allows users to create and execute stored procedures, functions, triggers, etc., using variables, loops, conditions, exceptions, etc., in addition to SQL commands. T-SQL helps improve the performance, functionality, modularity, and security of SQL queries and applications. The other options are either not related or not having both data manipulation and procedural scripting power. For example, PQL, or Power Query Language, is a data analysis andtransformation language for Microsoft Power BI and Excel; Advanced SQL is a term that refers to the advanced features or techniques of SQL, such as subqueries, joins, aggregations, etc.; SQL, or Structured Query Language, is a standard language for manipulating and querying data in relational databases, but it does not have procedural features. References: CompTIA DataSys+ Course Outline, Domain 1.0 Database Fundamentals, Objective 1.2 Given a scenario, execute database tasks using scripting and programming languages.

• Question 20:

  Which of the following is a reason to create a stored procedure?

  A. To minimize storage space
  B. To improve performance
  C. To bypass case sensitivity requirements
  D. To give control of the query logic to the user
  B. To improve performance

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  Explanation/Reference:

  A reason to create a stored procedure is to improve performance. A stored procedure is a set of SQL statements or commands that are stored and compiled in the database server, and can be executed by name or by a trigger. A stored procedure can improve performance by reducing the network traffic between the client and the server, as only the name or the parameters of the stored procedure need to be sent, rather than the entire SQL code. A stored procedure can also improve performance by reusing the same execution plan, as the stored procedure is compiled only once and cached in the server memory. The other options are either not true or not relevant for this purpose. For example, a stored procedure does not necessarily minimize storage space, as it still occupies space in the database server; a stored procedure does not bypass case sensitivity requirements, as it still follows the rules of the database system; a stored procedure does not give control of the query logic to the user, as it is defined and maintained by the database administrator or developer. References: CompTIA DataSys+ Course Outline, Domain 2.0 Database Deployment, Objective 2.2

  Given a scenario, create database objects using scripting and programming languages.