CompTIA DS0-001 Practice Test - Questions Answers

The advantage of creating indexes is to provide quick and efficient access to data. An index is a data structure that stores the values of one or more columns of a table in a sorted order, along with pointers to the corresponding rows in the table. An index helps to speed up queries that search, filter, sort, or join data based on the indexed columns, as it reduces the number of disk accesses or scans required to locate the desired data. An index also helps to enforce uniqueness or referential integrity constraints on the indexed columns. The other options are either not true or not relevant for this purpose. For example, an index does not help with space allocation, as it consumes additional space in the database; an index does not reduce memory, as it may use memory for caching or buffering purposes; an index does not update the query plan, as it is an input or a factor for the query optimizer to generate the query plan.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 option that is most likely to prevent tampering with server hardware that houses data is biometric locks. Biometric locks are devices that use biological characteristics, such as fingerprints, facial recognition, iris scan, etc., to control access to a physical location or resource. Biometric locks help prevent tampering with server hardware that houses data by restricting unauthorized entry or theft of the hardware by intruders or attackers. Biometric locks also provide higher security and convenience than other types of locks, such as keys or passwords, which can be lost, stolen, or forgotten. The other options are either not related or not effective for this purpose. For example, a strong password policy is a set of rules or standards for creating and managing passwords for user accounts or systems; a network firewall is a device or software that controls the incoming and outgoing traffic on a network based on a set of rules or policies; surveillance cameras are devices that capture and record video footage of a physical location or resource.Reference:CompTIA DataSys+ Course Outline, Domain 4.0 Data and Database Security, Objective 4.2 Given a scenario, implement security controls for databases.

The purpose of a snapshot is to create an image of a database. A snapshot is a copy of the state and content of a database at a specific point in time. A snapshot can be used for various purposes, such as backup and recovery, testing and development, reporting and analysis, etc. A snapshot can be created using various techniques, such as full copy, incremental copy, differential copy, etc. A snapshot can also be created using various tools or commands provided by the database system or software. The other options are either incorrect or irrelevant for this question. For example, dynamic data replication is a process that copies and synchronizes data from one database server (the source) to one or more database servers (the target) in real time; a synonym is an alias or an alternative name for an object in a database; C is an incomplete option.Reference:CompTIA DataSys+ Course Outline, Domain 5.0 Business Continuity, Objective 5.2 Given a scenario, implement backup and restoration of database management systems.

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.

The characteristic of all non-relational databases is unstructured data. Unstructured data is data that does not have a predefined or fixed format, schema, or structure. Unstructured data can include various types of data, such as text, images, audio, video, etc. Non-relational databases, also known as NoSQL databases, are databases that store and manage unstructured data using different models, such as key-value, document, graph, columnar, etc. Non-relational databases are suitable for handling large volumes, variety, and velocity of data that do not fit well in the relational model. The other options are either characteristics of relational databases or not related to database types at all. For example, columns with the same data type, logical record groupings, and tabular schema are characteristics of relational databases, which are databases that store and manage structured data using tables, rows, columns, and constraints.Reference:CompTIA DataSys+ Course Outline, Domain 1.0 Database Fundamentals, Objective 1.1 Given a scenario, identify common database types.

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.Reference:CompTIA DataSys+ Course Outline, Domain 4.0 Data and Database Security, Objective 4.2 Given a scenario, implement security controls for databases.

The factor that the administrator should measure to analyze a database server's disk throughput is IOPS. IOPS, or Input/Output Operations Per Second, is a metric that measures the number of read and write operations that a disk can perform in one second. IOPS indicates the performance or speed of a disk and how well it can handle multiple requests or transactions. Higher IOPS means higher disk throughput and lower latency. IOPS can be affected by various factors, such as disk type, size, speed, cache, RAID level, etc. The other options are either not related or not sufficient for this purpose. For example, RPfvl is not a valid acronym or metric; latency is the time delay between a request and a response; reads are the number of read operations performed by a disk.Reference:CompTIA DataSys+ Course Outline, Domain 3.0 Database Management and Maintenance, Objective 3.2 Given a scenario, monitor database performance.

The two options that have data manipulation and procedural scripting power are PL/SQL and T-SQL. PL/SQL, or Procedural Language/Structured Query Language, is an extension of SQL that adds procedural features to SQL for Oracle databases. PL/SQL allows users to create and execute stored procedures, functions, triggers, packages, etc., using variables, loops, conditions, exceptions, etc., in addition to SQL commands. PL/SQL helps improve the performance, functionality, modularity, and security of SQL queries and applications. T-SQL, or Transact-SQL, is an extension of SQL that adds procedural features to SQL for Microsoft SQL Server databases. T-SQL allows users to create and execute stored procedures, functions, triggers, etc., using variables, loops, conditions, exceptions, etc., in addition to SQL commands. T-SQL helps improve the performance, functionality, modularity, and security of SQL queries and applications. The other options are either not related or not having both data manipulation and procedural scripting power. For example, PQL, or Power Query Language, is a data analysis and transformation language for Microsoft Power BI and Excel; Advanced SQL is a term that refers to the advanced features or techniques of SQL, such as subqueries, joins, aggregations, etc.; SQL, or Structured Query Language, is a standard language for manipulating and querying data in relational databases, but it does not have procedural features.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 most likely causes of the reporting application not working are that the access permissions for the service account used by the reporting application were not changed, and that the reporting application's mapping to the database location was not updated. These two factors could prevent the reporting application from accessing the new database server. The other options are either irrelevant or unlikely to cause the problem.Reference:CompTIA DataSys+ Course Outline, Domain 3.0 Database Management and Maintenance, Objective 3.2 Given a scenario, troubleshoot common database issues.