CompTIA DS0-001 Exam With Confidence Using Practice Dumps

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.

 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.

The option that is used to hide data in a database so the data can only be read by a user who has a key is data encryption. Data encryption is a process that transforms data into an unreadable or scrambled form using an algorithm and a key. Data encryption helps protect data from unauthorized access or modification by third parties, such as hackers, eavesdroppers, or interceptors. Data encryption also helps verify the identity and authenticity of the source and destination of the data using digital signatures or certificates. Data encryption can be applied to data at rest (stored in a database) or data in transit (transmitted over a network). To read encrypted data, a user needs to have the corresponding key to decrypt or restore the data to its original form. The other options are either different concepts or not related to hiding data at all. For example, data security is a broad term that encompasses various methods and techniques to protect data from threats or risks; data masking is a technique that replaces sensitive data with fictitious but realistic data to protect its confidentiality or compliance; data protection is a term that refers to the legal or ethical obligations to safeguard personal or sensitive data from misuse or harm. References: CompTIA DataSys+ Course Outline, Domain 4.0 Data and Database Security, Objective 4.2 Given a scenario, implement security controls for databases.