CompTIA DS0-001 Exam With Confidence Using Practice Dumps

The SQL command that the administrator should use to ensure that records from the two tables are not duplicated is option A. This command uses the UNION clause to combine the records from the legacy table and the newer table into a single result set. The UNION clause also eliminates any duplicate records that may exist in both tables, and sorts the result by default. The other options either do not produce the desired result or have syntax errors. For example, option B would join the records from the two tables based on a common column, but not remove any duplicates; option C would return only the records that are common to both tables, but not the ones that are unique to each table; option D would produce a Cartesian product of the records from the two tables, which would increase the number of duplicates. 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 database administrator should mask the sensitive data before giving the developers access to the environment. Data masking is a technique that replaces sensitive data with fictitious but realistic data, such as random numbers or characters, to protect it from unauthorized access or exposure. Data masking preserves the format and structure of the original data, but does notreveal its actual value. This allows developers to work with realistic data without compromising its confidentiality or compliance. The other options are either insufficient or excessive for this scenario. For example, auditing access to tables with sensitive data may help monitor and track who accesses the data, but does not prevent it from being seen; removing sensitive data from tables may compromise the quality or completeness of the data, and may not be feasible if there is a large amount of data; encrypting connections to the development environment may protect the data in transit, but not at rest or in use. References: CompTIA DataSys+ Course Outline, Domain 4.0 Data and Database Security, Objective 4.2 Given a scenario, implement security controls for databases.

The best way to migrate a large data load from one table to another, considering total time and blocking, is to batch into small loads and run in parallel. This means that the large data load is divided into smaller chunks that can be processed simultaneously by multiple threads or processes. This reduces the total time required for the migration and also minimizes the blocking of other operations on the tables involved. The other options are either less efficient or more prone to blocking. For example, splitting the load size into many transactions may increase the overhead and latency of each transaction; splitting the load size in half and running simultaneously may still cause blocking or contention; batching large loads into one transaction may take longer and lock the tables for longer periods. References: CompTIA DataSys+ Course Outline, Domain 3.0 Database Management and Maintenance, Objective 3.3 Given a scenario, migrate data between databases.