Free Practice Questions for CompTIA DS0-001 Exam

Answer : C

The command that the database administrator should use for this task is CREATE USER. The CREATE USER command is a SQL statement that creates a new user account in a database and assigns it a username and a password. The CREATE USER command also allows the database administrator to specify other options or attributes for the user account, such as default tablespace, quota, profile, role, etc. The CREATE USER command is the first step to enable a user to authenticate to a database. The other options are either invalid or not suitable for this task. For example, INSERT USER is not a valid SQL command; ALLOW USER is not a SQL command, but a keyword used in some database systems to grant permissions to users; ALTER USER is a SQL command that modifies an existing user account, but does not create a new one.Reference:CompTIA DataSys+ Course Outline, Domain 4.0 Data and Database Security, Objective 4.2 Given a scenario, implement security controls for databases.

Answer : A

The index that the developer should use to prevent duplicate values from being inserted is unique. A unique index is a type of index that enforces the uniqueness of the values in one or more columns of a table. A unique index ensures that no two rows in the table have the same value or combination of values in the indexed columns. A unique index helps to maintain data integrity and avoid data duplication or inconsistency. The other options are either not related or not effective for this purpose. For example, a single column index is a type of index that involves only one column of a table, but it does not prevent duplicate values unless it is also unique; an implicit index is a type of index that is automatically created by the database system when a constraint or a primary key is defined on a column or columns of a table, but it does not prevent duplicate values unless it is also unique; a composite index is a type of index that involves two or more columns of a table, but it does not prevent duplicate values unless it is also unique.Reference:CompTIA DataSys+ Course Outline, Domain 1.0 Database Fundamentals, Objective 1.2 Given a scenario, execute database tasks using scripting and programming languages.

Answer : A, B

The two factors that the database administrator should monitor to gauge server health are CPU usage and memory usage. CPU usage is the percentage of time that the processor (CPU) of the server is busy executing instructions or processes. CPU usage indicates how much workload the server can handle and how fast it can process requests. High CPU usage may affect the performance or availability of the server and cause delays or errors. Memory usage is the amount of physical memory (RAM) or virtual memory (swap space) that the server uses to store data or run applications. Memory usage indicates how much space the server has to store temporary or intermediate data or results. High memory usage may affect the performance or availability of the server and cause swapping or paging. The other options are either not relevant or not direct indicators of server health. For example, transaction logs are files that record the changes made by transactions on the database; network sniffer is a tool that captures and analyzes network traffic; domain controllers are servers that manage user authentication and authorization in a network; firewall traffic is the amount of data that passes through a firewall device or software.Reference:CompTIA DataSys+ Course Outline, Domain 3.0 Database Management and Maintenance, Objective 3.2 Given a scenario, monitor database performance.

Answer : A

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.Reference:CompTIA DataSys+ Course Outline, Domain 1.0 Database Fundamentals, Objective 1.3 Given a scenario, identify common database issues.

Answer : B

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