DS0-001 Exam Dumps : CompTIA DataSys+ Certification Exam

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 valuesunlike a primary key; there is no such constraint as TID. 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 tool that is used for natively running a Linux system in Windows is WSL. WSL, or Windows Subsystem for Linux, is a feature that allows users to run a Linux system natively on Windows 10 or Windows Server. WSL enables users to install and use various Linux distributions, such as Ubuntu, Debian, Fedora, etc., and run Linux commands, tools, applications, etc., without requiring a virtual machine or a dual-boot setup. WSL also provides users with interoperability and integration between Linux and Windows, such as file system access, network communication, process management, etc. WSL is useful for users who want to use Linux features or functionalities on Windows, such as development, testing, scripting, etc. The other options are either different tools or not related to running a Linux system in Windows at all. For example, Remote Desktop Protocol (RDP) is a protocol that allows users to remotely access and control another computer or device over a network; SSH, or Secure Shell, is a protocol that allows users to securely connect and communicate with another computer or device over a network; Telnet is a protocol that allows users to interact with another computer or device over a network using a text-based interface. References: CompTIA DataSys+ Course Outline, Domain 2.0 Database Deployment, Objective 2.2 Given a scenario, create database objects using scripting and programming languages.

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.