CompTIA DS0-001 - CompTIA DataSys+ Certification Exam

A reason to create a stored procedure is to improve performance. A stored procedure is a set of SQL statements or commands that are stored and compiled in the database server, and can be executed by name or by a trigger. A stored procedure can improve performance by reducing the network traffic between the client and the server, as only the name or the parameters of the stored procedure need to be sent, rather than the entire SQL code. A stored procedure can also improve performance by reusing the same execution plan, as the stored procedure is compiled only once and cached in the server memory. The other options are either not true or not relevant for this purpose. For example, a stored procedure does not necessarily minimize storage space, as it still occupies space in the database server; a stored procedure does not bypass case sensitivity requirements, as it still follows the rules of the database system; a stored procedure does not give control of the query logic to the user, as it is defined and maintained by the database administrator or developer. 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 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. References: CompTIA DataSys+ Course Outline, Domain 1.0 Database Fundamentals, Objective 1.1 Given a scenario, identify common database types.

The property that addresses this concern is durability. Durability is one of the four properties (ACID) that ensure reliable transactions in a database system. Durability means that once a transaction has been committed, its effects are permanent and will not be lost in case of system failure, power outage, crash, etc. Durability can be achieved by using techniques such as write-ahead logging, checkpoints, backup and recovery, etc. The other options are either not related or not specific to this concern. For example, isolation means that concurrent transactions do not interfere with each other and produce consistent results; atomicity means that a transaction is either executed as a whole or not at all; consistency means that a transaction preserves the validity and integrity of the data. References: CompTIA DataSys+ Course Outline, Domain 1.0 Database Fundamentals, Objective 1.3 Given a scenario, identify common database issues.

The join that is most appropriate for the analyst to use to create this database view is option D. This join uses the LEFT JOIN clause to combine the client table and the invoice table based on the matching values in the Key column. The WHERE clause filters out the rows where the Invoice.Key column is not null, meaning that the client has made a purchase. The result is a view that shows only the clients who have not made any purchases yet. The other options either do not produce the desired result or have syntax errors. For example, option A would show only the clients who have made purchases, option B would show only the invoices that do not have a matching client, and option C would show all the clients regardless of their purchase status. 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 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 andtransformation 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. 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 factor that must be considered to ensure data integrity during transmission is encryption. Encryption is a process that transforms data into an unreadable or scrambled form using an algorithm and a key. Encryption helps protect data integrity during transmission by preventing unauthorized access or modification of data by third parties, such as hackers, eavesdroppers, or interceptors. Encryption also helps verify the identity and authenticity of the source and destination of the data using digital signatures or certificates. The other options are either not related or not sufficient for this purpose. For example, bandwidth is the amount of data that can be transmitted over a network in a given time; redundancy is the duplication of data or components to provide backup or alternative sources in case of failure; masking is a technique that replaces sensitive data with fictitious but realistic data to protect its confidentiality orcompliance. References: CompTIA DataSys+ Course Outline, Domain 4.0 Data and Database Security, Objective 4.2 Given a scenario, implement security controls for databases.

The query that the administrator should use to create the table is option B. This query uses the CREATE TABLE statement to define a new table named XYZ with three columns: ID, Name, and Age. Each column has a data type and a constraint, such as NOT NULL, PRIMARY KEY, or CHECK. The other options either have syntax errors, use incorrect keywords, or do not specify the table name or columns correctly. References: CompTIA DataSys+ Course Outline, Domain 1.0 Database Fundamentals, Objective 1.1 Given a scenario, identify and apply database structure types.

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. References: CompTIA DataSys+ Course Outline, Domain 1.0 Database Fundamentals, Objective 1.2 Given a scenario, execute database tasks using scripting and programming languages.

A result of an on-path attack on a system is a Wi-Fi network that redirects to clones of legitimate websites. An on-path attack is a type of attack that intercepts and modifies the traffic between two parties without their knowledge or consent. An attacker can use an on-path attack to create a rogue Wi-Fi network that mimics a legitimate one, and then redirect the users to fake websites that look like the ones they intended to visit. The attacker can then steal the users’ personal or financial information, such as usernames, passwords, credit card numbers, or bank account details. The other options are either results of different types of attacks or not related to attacks at all. For example, a website that has crashed and is no longer accessible may be a result of a denial-of-service attack, an email from an unknown source requesting bank account details may be a result of a phishing attack, and a web application that returns the addresses of its customers may be a result of a poor design or a data breach. References: CompTIA DataSys+ Course Outline, Domain 4.0 Data and Database Security, Objective 4.4 Given a scenario, identify common types of attacks against databases.

The first thing that the database administrator should examine to troubleshoot the issue is the event log. The event log is a file that records the events and activities that occur on a system, such as database backups, errors, warnings, or failures. By examining the event log, the administrator can identify the cause and time of the backup failure, and also check for any other issues or anomalies that may affect the backup process or the backup quality. The other options are either not relevant or not the first priority for this task. For example, CPU usage, disk space, and OS performance may affect the performance or availability of the system, but not necessarily cause the backup failure; moreover, these factors can be checked after reviewing the event log for more information. References: CompTIA DataSys+ Course Outline, Domain 5.0 Business Continuity, Objective 5.2 Given a scenario, implement backup and restoration of database management systems.