DS0-001 Exam Dumps : CompTIA DataSys+ Certification Exam

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 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.

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. References: CompTIA DataSys+ Course Outline, Domain 2.0 Database Deployment, Objective 2.2 Given a scenario, create database objects using scripting and programming languages.