SQL Server Management Studio (SSMS) is a popular tool for managing SQL Server databases, providing features for performance monitoring, query optimization, and administration tasks. DBeaver is a versatile database management tool that supports various database platforms and offers performance profiling capabilities to monitor database performance and troubleshoot issues.

Structural testing, also known as schema testing, ensures that the database schema follows the defined structure and constraints. It involves validating the database objects such as tables, columns, indexes, and relationships to ensure they conform to the specifications outlined in the schema design. This testing helps identify any discrepancies or errors in the database structure.

Scalability testing examines how a system handles increased workload. Horizontal scaling involves adding more resources, such as servers, to distribute the load across multiple machines. Therefore, as the term "horizontal" implies expansion across a wider base, it directly relates to the system's performance with increasing loads.

SQL stands for Structured Query Language. It is a standard language for interacting with relational databases. SQL is used to perform various operations such as inserting, updating, deleting, and retrieving data from databases. In the context of database testing, understanding SQL is crucial for writing and executing queries to validate the data and ensure the integrity of the database.

One of the challenges of using monitoring tools is handling large volumes of data generated during testing. This data can be overwhelming and may require efficient management and processing techniques to derive meaningful insights for performance optimization.

Data integrity ensures that data remains accurate, consistent, and reliable throughout its lifecycle. It involves maintaining the accuracy and consistency of data, preventing unauthorized access, and ensuring data reliability, which are crucial aspects in handling large data sets.

The correct option is "ROLLBACK." When starting a transaction with BEGIN TRANSACTION, it must be followed by a corresponding ROLLBACK statement to undo the changes made within the transaction if necessary.

The principle of "least privilege" dictates that users should be granted only the minimum level of access or permissions necessary to perform their tasks, reducing the risk of unauthorized access or misuse of sensitive data. This helps enhance security by limiting potential vulnerabilities.

ETL (Extract, Transform, Load) testing ensures the successful migration and transformation of data across various systems, databases, or applications. Therefore, the correct option is "Systems."

Integration tests are typically run as part of the CI/CD pipeline for database changes. These tests ensure that individual database components work together correctly, and integrations with other systems or modules are functioning as expected. They help catch issues early in the development process and ensure the overall stability and reliability of the database changes.

Automation frameworks for database testing need to support various database instances to cater to different database management systems. This flexibility ensures compatibility and effectiveness across diverse environments.

The DELETE statement is commonly exploited in SQL injection attacks because it allows attackers to delete data from the database, potentially causing data loss or manipulation.