CompTIA DS0-001 Exam

The resource that is the best way to lock rows in SQL Server is RID. RID, or Row IDentifier, is an attribute that uniquely identifies each row in a heap table in SQL Server. A heap table is a table that does not have a clustered index, which means that the rows are not stored in any particular order. A RID consists of the file number, page number, and slot number of the row in the database. A RID can be used to lock rows in SQL Server to prevent concurrent access or modification by other transactions or users. A RID lock is a type of lock that locks a single row using its RID. A RID lock can be applied using theHOLDLOCKorXLOCKhints in aSELECTstatement. The other options are either not related or not effective for this purpose. For example, TID, or Transaction IDentifier, is an attribute that uniquely identifies each transaction in a database; SID, or Security IDentifier, is an attribute that uniquely identifies each user or group in a Windows system; PID, or Process IDentifier, is an attribute that uniquely identifies each process in an operating system.Reference:CompTIA DataSys+ Course Outline, Domain 3.0 Database Management and Maintenance, Objective 3.3 Given a scenario, implement database concurrency methods.

The command that is part of DDL is CREATE. CREATE is a SQL command that belongs to the category of DDL, or Data Definition Language. DDL is a subset of SQL commands that are used to define or modify the structure or schema of a database, such as tables, columns, constraints, indexes, views, etc. CREATE is a DDL command that is used to create a new object in a database, such as a table, column, constraint, index, view, etc. For example, the following statement uses the CREATE command to create a new table called employee with four columns:

CREATE TABLE employee (

emp_id INT PRIMARY KEY,

emp_name VARCHAR(50) NOT NULL,

emp_dept VARCHAR(20),

emp_salary DECIMAL(10,2)

);

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The other options are either part of different categories of SQL commands or not SQL commands at all. For example, UPDATE is a SQL command that belongs to the category of DML, or Data Manipulation Language. DML is a subset of SQL commands that are used to manipulate or modify the data or content of a database, such as inserting, updating, deleting, or selecting data. GRANT is a SQL command that belongs to the category of DCL, or Data Control Language. DCL is a subset of SQL commands that are used to control or manage the access or permissions of users or roles on a database, such as granting or revoking privileges or roles. INSERT is a SQL command that belongs to the category of DML, or Data Manipulation Language. INSERT is a DML command that is used to insert new data into a table.Reference:CompTIA DataSys+ Course Outline, Domain 1.0 Database Fundamentals, Objective 1.2 Given a scenario, execute database tasks using scripting and programming languages.

The NoSQL database type that best categorizes MongoDB is document. Document databases are databases that store and manage data as documents, which are collections of fields and values in formats such as JSON (JavaScript Object Notation) or XML (Extensible Markup Language). Document databases do not use any schema or structure to organize data, but rather use identifiers or indexes to enable flexible and dynamic access to data based on fields or values. Document databases are suitable for storing large amounts of complex or unstructured data that have variable attributes or nested structures. MongoDB is an example of a document database that uses JSON-like documents to store and query data. The other options are either different types of NoSQL databases or not related to NoSQL databases at all. For example, column-oriented databases are databases that store and manage data as columns rather than rows; graph databases are databases that store and manage data as nodes and edges that represent entities and relationships; key-value stores are databases that store and manage data as pairs of keys and values.Reference:CompTIA DataSys+ Course Outline, Domain 1.0 Database Fundamentals, Objective 1.1 Given a scenario, identify common database types.

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

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.