Data integrity ensures that data remains accurate, consistent, and reliable throughout the migration process, preventing any discrepancies or errors.

Advanced test data generation tools employ techniques such as masking, encryption, data anonymization, and redaction to ensure data privacy and compliance with regulations. Masking involves replacing sensitive data with fictional data that retains the format of the original data but doesn't reveal its actual content. Encryption secures the data by encoding it, making it accessible only with the correct decryption key. Data anonymization involves removing personally identifiable information from the dataset. Redaction involves selectively removing or obscuring sensitive information from documents or datasets. These techniques help organizations protect sensitive information and comply with privacy regulations such as GDPR and HIPAA.

Database testing tools streamline and automate testing processes, thereby reducing the need for manual intervention. Option 1, "Manual," is the correct choice, as it signifies the reduction in manual effort through automation.

A Test Case is a pre-defined set of test data and expected results used during script execution. It outlines the steps to be executed, the input data, and the expected outcomes. Test Cases are crucial in ensuring comprehensive test coverage and evaluating the functionality of the system under test.

Test scenarios are executed in the database testing process to ensure that the database functions as expected under various conditions and scenarios.

SQL queries are commonly used by testers to compare data between source and target systems during database testing. These queries retrieve data from both systems and enable testers to perform comparisons, identify discrepancies, and validate the accuracy and completeness of data migration or transformation processes. SQL queries provide a powerful means for testers to verify the integrity and consistency of data across different systems.

Data validation in ETL processes ensures the integrity of data and verifies its completeness, guaranteeing data correctness throughout.

The unique constraint ensures that values in a column are unique within a table, thus maintaining data integrity by preventing duplicate entries.

In asymmetric encryption, the public key is used for encrypting data that can only be decrypted using the corresponding private key. Thus, the correct pair is Option 2. Option 1 is incorrect as the private key is used for decryption, not encryption. Option 3 is incorrect as asymmetric encryption is not primarily used for authentication. Option 4 is incorrect as it does not accurately represent the roles of public and private keys in asymmetric encryption.

Data integrity testing ensures that the data stored and retrieved remains free from corruption. Corruption in data can lead to inaccuracies and inconsistencies, which compromise the integrity of the database.