DS0-001 Exam Dumps : CompTIA DataSys+ Certification Exam

The backup plan that best describes the logs is weekly full, daily incremental. This means that a full backup of the entire database is performed once a week, and then only the changes made since the last backup are backed up every day. This can be inferred from the logs by looking at the size and duration of the backups. The full backups are larger and take longer than the incremental backups, and they occur every seven days. The other backup plans do not match the pattern of the logs. References: CompTIA DataSys+ Course Outline, Domain 5.0 Business Continuity, Objective 5.2 Given a scenario, implement backup and restoration of database management systems.

The two database instances that are created by default when SQL Server is installed are master and model. Master is a system database that contains the information and settings of the SQL Server instance, such as the configuration, logins, endpoints, databases, etc. Master is essential for the operation and management of the SQL Server instance, and it should be backed up regularly. Model is a system database that serves as a template for creating new user databases. Model contains the default settings and objects, such as tables, views, procedures, etc., that will be inherited by the new user databases. Model can be modified to customize the new user databases according to specific needs or preferences. The other options are either not database instances or not created by default when SQL Server is installed. For example, root is not a database instance, but a term that refers to the highest level of access or privilege in a system; log is not a database instance, but a file that records the changes made by transactions on a database; view is not a database instance, but an object that represents a subset or a combination of data from one or more tables; index is not a database instance, but a data structure that stores the values of one or more columns of a table in a sorted order. References: CompTIA DataSys+ Course Outline, Domain 2.0 Database Deployment, Objective 2.3 Given a scenario, update database systems.

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 values unlike 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.