The data mapping document specifies the relationships between the source and target systems, guiding the data migration process by detailing how data from various sources will be mapped to the corresponding target.

The correct option is "Summary". Test summary reports play a vital role in communicating key information about the testing process to stakeholders. These reports typically include essential metrics, trends, and findings from the testing activities, providing stakeholders with valuable insights into the quality of the product and areas that require attention.

Testing large datasets presents scalability challenges, where the database system's ability to handle increasing amounts of data efficiently is put to the test. Scalability issues involve ensuring that the system maintains its performance and responsiveness as the dataset size grows, avoiding performance bottlenecks that can hinder overall database functionality.

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.

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.

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.

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.

SQL query testing ensures that the SQL queries return the correct results according to the intended logic and requirements. It involves checking the accuracy, completeness, and efficiency of SQL queries. This helps in identifying any discrepancies or errors in the data retrieval process.

White box testing involves examining the internal structure of the SQL query to identify any logic errors or anomalies that may cause incorrect results. By analyzing the query's code and execution paths, you can pinpoint and rectify issues that affect data retrieval accuracy.

Automation frameworks facilitate consistent test execution, which is crucial for reliable and accurate results. Consistency ensures that tests are performed uniformly, reducing the likelihood of errors and inconsistencies.