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NEW QUESTION # 13
A database administrator is concerned about transactions in case the system fails. Which of the following properties addresses this concern?
- A. Atomicity
- B. Consistency
- C. Durability
- D. Isolation
Answer: C
Explanation:
The property that addresses this concern is durability. Durability is one of the four properties (ACID) that ensure reliable transactions in a database system. Durability means that once a transaction has been committed, its effects are permanent and will not be lost in case of system failure, power outage, crash, etc. Durability can be achieved by using techniques such as write-ahead logging, checkpoints, backup and recovery, etc. The other options are either not related or not specific to this concern. For example, isolation means that concurrent transactions do not interfere with each other and produce consistent results; atomicity means that a transaction is either executed as a whole or not at all; consistency means that a transaction preserves the validity and integrity of the data. Reference: CompTIA DataSys+ Course Outline, Domain 1.0 Database Fundamentals, Objective 1.3 Given a scenario, identify common database issues.
NEW QUESTION # 14
Which of the following is recommended in order to provide encrypted data communication pathways for information as it is transmitted over a network?
- A. TCP/IP
- B. NFS
- C. SMB
- D. TLS
Answer: D
Explanation:
The option that is recommended in order to provide encrypted data communication pathways for information as it is transmitted over a network is TLS. TLS, or Transport Layer Security, is a protocol that provides secure communication over the internet by encrypting the data using cryptographic algorithms and keys. TLS also provides authentication and integrity by verifying the identity of the parties involved and ensuring that the data has not been altered or tampered with. TLS can be used to protect various types of data, such as web traffic, email, instant messaging, voice over IP, etc. The other options are either not related or not sufficient for this purpose. For example, TCP/IP, or Transmission Control Protocol/Internet Protocol, is a set of protocols that defines how data is transmitted and routed over the internet, but does not provide encryption or security; NFS, or Network File System, is a protocol that allows users to access and share files over a network, but does not provide encryption or security; SMB, or Server Message Block, is a protocol that allows users to access and share files, printers, and other resources over a network, but does not provide encryption or security. Reference: CompTIA DataSys+ Course Outline, Domain 4.0 Data and Database Security, Objective 4.2 Given a scenario, implement security controls for databases.
NEW QUESTION # 15
Which of the following constraints is used to enforce referential integrity?
- A. Primary key
- B. Foreign key
- C. Unique key
- D. Surrogate key
Answer: B
Explanation:
The constraint that is used to enforce referential integrity is foreign key. A foreign key is a column or a set of columns in a table that references the primary key of another table. A primary key is a column or a set of columns in a table that uniquely identifies each row in the table. Referential integrity is a rule that ensures that the values in the foreign key column match the values in the primary key column of the referenced table. Referential integrity helps maintain the consistency and accuracy of the data across related tables. The other options are either different types of constraints or not related to referential integrity at all. For example, a surrogate key is a column that is artificially generated to serve as a primary key, such as an auto-increment number or a GUID (Globally Unique Identifier); a unique key is a column or a set of columns in a table that uniquely identifies each row in the table, but it can have null values unlike a primary key; there is no such constraint as TID. Reference: CompTIA DataSys+ Course Outline, Domain 1.0 Database Fundamentals, Objective 1.2 Given a scenario, execute database tasks using scripting and programming languages.
NEW QUESTION # 16
A DBA left the company, and the DBA's account was removed from the system. Soon after, scheduled jobs began failing.
Which of the following would have most likely prevented this issue?
- A. Load balancing
- B. Business continuity plan
- C. Service accounts
- D. Assigning a data steward
Answer: C
Explanation:
The most likely way to prevent this issue is to use service accounts. Service accounts are special accounts that are used by applications or services to perform tasks or run jobs on behalf of users. Service accounts have limited permissions and access rights that are tailored to their specific functions. By using service accounts, the DBA can ensure that scheduled jobs can run independently of individual user accounts, and avoid failures due to account removal or changes. The other options are either not related or not effective for this issue. For example, load balancing is a technique that distributes the workload across multiple servers or resources to improve performance and availability; business continuity plan is a plan that outlines how an organization will continue its operations in the event of a disaster or disruption; assigning a data steward is a process that designates a person who is responsible for ensuring the quality and governance of data. Reference: CompTIA DataSys+ Course Outline, Domain 3.0 Database Management and Maintenance, Objective 3.3 Given a scenario, migrate data between databases.
NEW QUESTION # 17
Which of the following is most likely to prevent tampering with server hardware that houses data?
- A. Surveillance cameras
- B. Network firewall
- C. Biometric locks
- D. Strong password policy
Answer: C
Explanation:
The option that is most likely to prevent tampering with server hardware that houses data is biometric locks. Biometric locks are devices that use biological characteristics, such as fingerprints, facial recognition, iris scan, etc., to control access to a physical location or resource. Biometric locks help prevent tampering with server hardware that houses data by restricting unauthorized entry or theft of the hardware by intruders or attackers. Biometric locks also provide higher security and convenience than other types of locks, such as keys or passwords, which can be lost, stolen, or forgotten. The other options are either not related or not effective for this purpose. For example, a strong password policy is a set of rules or standards for creating and managing passwords for user accounts or systems; a network firewall is a device or software that controls the incoming and outgoing traffic on a network based on a set of rules or policies; surveillance cameras are devices that capture and record video footage of a physical location or resource. Reference: CompTIA DataSys+ Course Outline, Domain 4.0 Data and Database Security, Objective 4.2 Given a scenario, implement security controls for databases.
NEW QUESTION # 18
Which of the following cloud delivery models provides users with the highest level of flexibility regarding resource provisioning and administration?
- A. DBaaS
- B. IaaS
- C. PaaS
- D. SaaS
Answer: B
Explanation:
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. Reference: CompTIA DataSys+ Course Outline, Domain 2.0 Database Deployment, Objective 2.1 Given a scenario, select an appropriate database deployment method.
NEW QUESTION # 19
Which of the following is part of logical database infrastructure security?
- A. Biometric access
- B. Surveillance
- C. Perimeter network
- D. Cooling system
Answer: C
Explanation:
The option that is part of logical database infrastructure security is perimeter network. Perimeter network, also known as DMZ (Demilitarized Zone), is a network segment that lies between an internal network and an external network, such as the internet. Perimeter network provides an additional layer of security for the internal network by isolating and protecting the servers or services that are exposed to the external network, such as web servers, email servers, database servers, etc. Perimeter network also helps prevent unauthorized access or attacks from the external network to the internal network by using firewalls, routers, proxies, etc. The other options are either part of physical database infrastructure security or not related to database infrastructure security at all. For example, surveillance is a method of monitoring and recording physical activities or events in a location or resource; biometric access is a device that uses biological characteristics to control access to a physical location or resource; cooling system is a device or system that regulates the temperature and humidity of a location or resource. Reference: CompTIA DataSys+ Course Outline, Domain 4.0 Data and Database Security, Objective 4.1 Given a scenario, implement database infrastructure security.
NEW QUESTION # 20
Over the weekend, a company's transaction database was moved to an upgraded server. All validations performed after the migration indicated that the database was functioning as expected. However, on Monday morning, multiple users reported that the corporate reporting application was not working.
Which of the following are the most likely causes? (Choose two.)
- A. The reporting application cannot keep up with the new, faster response from the database.
- B. The reporting application's mapping to the database location was not updated.
- C. The database server is not permitted to fulfill requests from a reporting application.
- D. The reporting jobs that could not process during the database migration have locked the application.
- E. The access permissions for the service account used by the reporting application were not changed.
- F. The new database server has its own reporting system, so the old one is not needed.
Answer: B,E
Explanation:
The most likely causes of the reporting application not working are that the access permissions for the service account used by the reporting application were not changed, and that the reporting application's mapping to the database location was not updated. These two factors could prevent the reporting application from accessing the new database server. The other options are either irrelevant or unlikely to cause the problem. Reference: CompTIA DataSys+ Course Outline, Domain 3.0 Database Management and Maintenance, Objective 3.2 Given a scenario, troubleshoot common database issues.
NEW QUESTION # 21
A database professional is considering denormalizing a database. Which of the following documents should be used to analyze the database's structure?
- A. Data dictionaries
- B. SOP
- C. ERD
- D. UML diaqrams
Answer: C
Explanation:
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. By using 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). Reference: CompTIA DataSys+ Course Outline, Domain 2.0 Database Deployment, Objective 2.2 Given a scenario, create database objects using scripting and programming languages.
NEW QUESTION # 22
A database's daily backup failed. Previous backups were completed successfully. Which of the following should the database administrator examine first to troubleshoot the issue?
- A. CPU usage
- B. OS performance
- C. Event log
- D. Disk space
Answer: C
Explanation:
The first thing that the database administrator should examine to troubleshoot the issue is the event log. The event log is a file that records the events and activities that occur on a system, such as database backups, errors, warnings, or failures. By examining the event log, the administrator can identify the cause and time of the backup failure, and also check for any other issues or anomalies that may affect the backup process or the backup quality. The other options are either not relevant or not the first priority for this task. For example, CPU usage, disk space, and OS performance may affect the performance or availability of the system, but not necessarily cause the backup failure; moreover, these factors can be checked after reviewing the event log for more information. Reference: CompTIA DataSys+ Course Outline, Domain 5.0 Business Continuity, Objective 5.2 Given a scenario, implement backup and restoration of database management systems.
NEW QUESTION # 23
Which of the following is a result of an on-path attack on a system?
- A. An email from an unknown source requesting bank account details
- B. A Wi-Fi network that redirects to clones of legitimate websites
- C. A website that has crashed and is no longer accessible
- D. A web application that returns the addresses of its customers
Answer: B
Explanation:
A result of an on-path attack on a system is a Wi-Fi network that redirects to clones of legitimate websites. An on-path attack is a type of attack that intercepts and modifies the traffic between two parties without their knowledge or consent. An attacker can use an on-path attack to create a rogue Wi-Fi network that mimics a legitimate one, and then redirect the users to fake websites that look like the ones they intended to visit. The attacker can then steal the users' personal or financial information, such as usernames, passwords, credit card numbers, or bank account details. The other options are either results of different types of attacks or not related to attacks at all. For example, a website that has crashed and is no longer accessible may be a result of a denial-of-service attack, an email from an unknown source requesting bank account details may be a result of a phishing attack, and a web application that returns the addresses of its customers may be a result of a poor design or a data breach. Reference: CompTIA DataSys+ Course Outline, Domain 4.0 Data and Database Security, Objective 4.4 Given a scenario, identify common types of attacks against databases.
NEW QUESTION # 24
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. Implicit
- B. Composite
- C. Single column
- D. Unique
Answer: D
Explanation:
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. Reference: CompTIA DataSys+ Course Outline, Domain 1.0 Database Fundamentals, Objective 1.2 Given a scenario, execute database tasks using scripting and programming languages.
NEW QUESTION # 25
Which of the following is a typical instruction that is found on a Linux command-line script and represents a system shell?
- A. /bin/bash
- B. >/bin/sh
- C. #/bin/shell
- D. #!/bin/bash
Answer: D
Explanation:
The instruction that is found on a Linux command-line script and represents a system shell is #!/bin/bash. This instruction is called a shebang or a hashbang, and it indicates the interpreter that should be used to execute the script. In this case, the interpreter is /bin/bash, which is the path to the bash shell, a common system shell for Linux. A system shell is a program that provides an interface for users to interact with the operating system, either through commands or scripts. A system shell can also perform various tasks, such as file management, process control, variable assignment, etc. The other options are either incorrect or not typical for this purpose. For example, /bin/bash is the path to the bash shell, but it does not indicate the interpreter for the script; #/bin/shell is not a valid shebang or a path to a system shell; >/bin/sh is a redirection operator followed by a path to a system shell, but it does not indicate the interpreter for the script. Reference: CompTIA DataSys+ Course Outline, Domain 2.0 Database Deployment, Objective 2.2 Given a scenario, create database objects using scripting and programming languages.
NEW QUESTION # 26
Which of the following services is responsible for assigning, managing, and reclaiming IP addresses on a TCP/IP-based network?
- A. ISMTP
- B. DHCP
- C. DNS
- D. LDAP
Answer: B
Explanation:
The service that is responsible for assigning, managing, and reclaiming IP addresses on a TCP/IP-based network is DHCP. DHCP, or Dynamic Host Configuration Protocol, is a service that automatically assigns IP addresses and other network configuration parameters, such as subnet mask, default gateway, DNS server, etc., to computers or devices on a network. DHCP helps simplify the administration and management of IP addresses on a network, as well as avoid conflicts or errors caused by manual or duplicate assignments. DHCP also allows computers or devices to release or renew their IP addresses when they join or leave the network. The other options are either different services or not related to IP addresses at all. For example, DNS, or Domain Name System, is a service that translates domain names into IP addresses and vice versa; LDAP, or Lightweight Directory Access Protocol, is a service that provides access to directory information such as users, groups, or devices on a network; ISMTP is not a valid acronym or service. Reference: CompTIA DataSys+ Course Outline, Domain 2.0 Database Deployment, Objective 2.1 Given a scenario, select an appropriate database deployment method.
NEW QUESTION # 27
Which of the following statements contains an error?
- A. Select EmpId from employee where EmpId=90030
- B. Select* from employee where EmpId=90030
- C. Select EmpId from employee
- D. Select EmpId where EmpId=90030 and DeptId=34
Answer: D
Explanation:
The statement that contains an error is option B. This statement is missing the FROM clause, which specifies the table or tables from which to retrieve data. The FROM clause is a mandatory clause in a SELECT statement, unless the statement uses a subquery or a set operator. The correct syntax for option B would be:
SELECT EmpId FROM employee WHERE EmpId=90030 AND DeptId=34
Copy
The other options are either correct or valid SQL statements. For example, option A selects the employee ID from the employee table where the employee ID is equal to 90030; option C selects all columns from the employee table where the employee ID is equal to 90030; option D selects the employee ID from the employee table without any filter condition. Reference: CompTIA DataSys+ Course Outline, Domain 1.0 Database Fundamentals, Objective 1.2 Given a scenario, execute database tasks using scripting and programming languages.
NEW QUESTION # 28
Following a security breach, a database administrator needs to ensure users cannot change data unless a request is approved by the management team. Which of the following principles addresses this issue?
- A. Elevated privilege
- B. Open access
- C. Least resistance
- D. Least privilege
Answer: D
Explanation:
The principle that addresses this issue is least privilege. Least privilege is a security principle that states that users should only have the minimum level of access or permissions required to perform their tasks or roles. By applying this principle, the administrator can ensure that users cannot change data unless they have been authorized by the management team through a request approval process. This prevents unauthorized or accidental modifications of data that may compromise its integrity or security. The other options are either opposite or unrelated to this principle. For example, open access means that users have unrestricted access to data; least resistance means that users have the easiest or most convenient access to data; elevated privilege means that users have higher or more permissions than they need. Reference: CompTIA DataSys+ Course Outline, Domain 4.0 Data and Database Security, Objective 4.1 Given a scenario, apply security principles and best practices for databases.
NEW QUESTION # 29
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. Write queries directly into the database and report findings.
- B. Check the clustered and non-clustered indexes, and report findings.
- C. Capture business logic, check the performance of codes, and report findings.
- D. Review application tables and columns, and report findings.
Answer: C
Explanation:
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. Reference: CompTIA DataSys+ Course Outline, Domain 4.0 Data and Database Security, Objective 4.3 Given a scenario, monitor database performance and security.
NEW QUESTION # 30
A database administrator is updating an organization's ERD. Which of the following is the best option for the database administrator to use?
- A. HTML editor
- B. UML tool
- C. Spreadsheet
- D. Word processor
Answer: B
Explanation:
The best option for the database administrator to use to update an organization's ERD is a UML tool. A UML tool is a software application that allows users to create, edit, and visualize diagrams using the Unified Modeling Language (UML). UML is a standard language for modeling software systems and their components, such as classes, objects, relationships, behaviors, etc. UML can also be used to create entity relationship diagrams (ERDs), which are graphical representations of the entities (tables), attributes (columns), and relationships (constraints) in a database. A UML tool can help the administrator to update an organization's ERD by providing features such as drag-and-drop, templates, symbols, validation, etc. The other options are either not suitable or not optimal for this task. For example, a word processor is a software application that allows users to create and edit text documents; a spreadsheet is a software application that allows users to organize and manipulate data in rows and columns; an HTML editor is a software application that allows users to create and edit web pages using HyperText Markup Language (HTML). Reference: CompTIA DataSys+ Course Outline, Domain 2.0 Database Deployment, Objective 2.2 Given a scenario, create database objects using scripting and programming languages.
NEW QUESTION # 31
A database administrator needs to aggregate data from multiple tables in a way that does not impact the original tables, and then provide this information to a department. Which of the following is the best way for the administrator to accomplish this task?
- A. Create a materialized view.
- B. Create a function.
- C. Create a new database.
- D. Create indexes on those tables
Answer: A
Explanation:
The best way for the administrator to accomplish this task is to create a materialized view. A materialized view is a type of view that stores the result of a query on one or more tables as a separate table in the database. A materialized view can aggregate data from multiple tables in a way that does not impact the original tables, and then provide this information to a department as a single source of truth. A materialized view also improves query performance and efficiency by reducing the need to recompute complex queries every time they are executed. The other options are either not suitable or not optimal for this task. For example, creating indexes on those tables may improve query performance on individual tables, but not on aggregated data; creating a new database may require additional resources and maintenance, and may introduce inconsistency or redundancy; creating a function may require additional coding and execution, and may not store the result as a separate table. Reference: CompTIA DataSys+ Course Outline, Domain 2.0 Database Deployment, Objective 2.2 Given a scenario, create database objects using scripting and programming languages.
NEW QUESTION # 32
Which of the following cloud storage options provides users with endpoints to retrieve data via REST API?
- A. Object
- B. Ephemeral
- C. iBIock
- D. Network file
Answer: A
Explanation:
The cloud storage option that provides users with endpoints to retrieve data via REST API is object. Object storage is a type of cloud storage that stores data as objects, which consist of data, metadata, and a unique identifier. Object storage does not use any hierarchy or structure to organize data, but rather uses flat namespaces that allow users to access data using the unique identifier. Object storage also provides users with endpoints to retrieve data via REST API (Representational State Transfer Application Programming Interface), which is a standard way of communicating with web services using HTTP methods (such as GET, POST, PUT, DELETE) and formats (such as JSON, XML). Object storage is suitable for storing large amounts of unstructured data that do not require frequent changes or complex queries. The other options are either different types of cloud storage or not related to cloud storage at all. For example, network file storage is a type of cloud storage that stores data as files in folders using protocols such as NFS (Network File System) or SMB (Server Message Block); ephemeral storage is a type of temporary storage that stores data only for the duration of a session or process; iBIock is not a valid acronym or type of cloud storage. Reference: CompTIA DataSys+ Course Outline, Domain 2.0 Database Deployment, Objective 2.1 Given a scenario, select an appropriate database deployment method.
NEW QUESTION # 33
Which of the following describes the purpose of a snapshot?
- A. To create a dynamic data replication
- B. To create an image of a database
- C. To create a synonym
- D. To create a
Answer: B
Explanation:
The purpose of a snapshot is to create an image of a database. A snapshot is a copy of the state and content of a database at a specific point in time. A snapshot can be used for various purposes, such as backup and recovery, testing and development, reporting and analysis, etc. A snapshot can be created using various techniques, such as full copy, incremental copy, differential copy, etc. A snapshot can also be created using various tools or commands provided by the database system or software. The other options are either incorrect or irrelevant for this question. For example, dynamic data replication is a process that copies and synchronizes data from one database server (the source) to one or more database servers (the target) in real time; a synonym is an alias or an alternative name for an object in a database; C is an incomplete option. Reference: CompTIA DataSys+ Course Outline, Domain 5.0 Business Continuity, Objective 5.2 Given a scenario, implement backup and restoration of database management systems.
NEW QUESTION # 34
Which of the following database structures is a type of NoSQL database?
- A. Key-value stores
- B. Cloud
- C. Hierarchical
- D. Object-oriented
Answer: A
Explanation:
The database structure that is a type of NoSQL database is key-value stores. Key-value stores are databases that store and manage data as pairs of keys and values. Keys are unique identifiers that locate data in the database; values are arbitrary data that can be any type or format. Key-value stores do not use any schema or structure to organize data, but rather use hash tables or indexes to enable fast and simple access to data based on keys. Key-value stores are suitable for storing large amounts of simple or unstructured data that do not require complex queries or relationships. The other options are either different types of databases or not related to database structures at all. For example, hierarchical databases are databases that store and manage data as nodes in a tree-like structure; cloud databases are databases that are hosted and accessed over the internet using cloud computing services; object-oriented databases are databases that store and manage data as objects that have attributes and methods. Reference: CompTIA DataSys+ Course Outline, Domain 1.0 Database Fundamentals, Objective 1.1 Given a scenario, identify common database types.
NEW QUESTION # 35
Which of the following best describes the category of SQL commands required to revoke access to database objects?
- A. DCL
- B. TCL
- C. IDML
- D. IDDL
Answer: A
Explanation:
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. Reference: CompTIA DataSys+ Course Outline, Domain 4.0 Data and Database Security, Objective 4.2 Given a scenario, implement security controls for databases.
NEW QUESTION # 36
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 is most appropriate for the analyst to use to create this database view?
- A. LEFT JOIN ON Client.Key = Invoice.Key WHERE BY Invoice.Key IS NOLL
- B. LEFT JOIN ON Client.Key = Invoice.Key
- C. RIGHT JOIN ON Client.Key = Invoice.Key WHERE BY Client.Key IS NOLL
- D. INNER JOIN ON Client.Key = Invoice.Key
Answer: A
Explanation:
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. Reference: CompTIA DataSys+ Course Outline, Domain 1.0 Database Fundamentals, Objective 1.2 Given a scenario, execute database tasks using scripting and programming languages.
NEW QUESTION # 37
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