Data migration testing often faces challenges such as data mapping errors where data from the source doesn't align correctly with the target, leading to inconsistencies and issues in migration.

Symmetric encryption uses a single key for both encryption and decryption, making it faster and more efficient for large volumes of data. Asymmetric encryption, on the other hand, uses a pair of keys (public and private) which makes it slower but more secure. Symmetric encryption is commonly used in database encryption because it provides faster processing times, essential for handling large amounts of data in databases.

Test coverage metric helps in identifying the percentage of test cases that have been executed but are still failing. It measures the extent to which the application has been tested by comparing the number of executed test cases to the total number of test cases defined in the test plan. A high test coverage percentage indicates that a significant portion of the application has been tested, while a low test coverage percentage suggests inadequate testing. By monitoring test coverage, testers can prioritize testing efforts, identify areas with insufficient coverage, and ensure comprehensive testing of the application. This metric is essential for assessing the thoroughness and effectiveness of the testing process.

The purpose of database query optimization in performance testing is to improve query efficiency. By optimizing queries, database performance can be enhanced, leading to faster response times, reduced resource consumption, and improved overall system performance. Query optimization techniques include index usage, query rewriting, and database schema tuning.

Automation frameworks aid in the creation of reusable test data for recurring testing scenarios. This improves efficiency by eliminating the need to recreate test data for each test cycle.

The principle of "least privilege" ensures that users have the minimum level of access necessary to accomplish their tasks. This practice reduces the risk of unauthorized access and potential security breaches.

The correct option is "Verifications." Test script execution should include verifications to validate that the expected outcomes are met. Verifications involve comparing the actual results of the executed test script with the expected outcomes specified beforehand. This ensures that the database behaves as intended and that any deviations from expected behavior are detected and addressed promptly.

Performance Testing

Data lineage analysis in ETL testing involves tracing the path or journey of data from its source to its destination or target, helping ensure data integrity and understand the data flow.

Storing credit card information in an unencrypted form violates PCI DSS compliance requirements. The immediate action should be to encrypt the credit card information using industry-standard encryption algorithms to ensure data security and compliance with PCI DSS standards. Encryption protects sensitive information from unauthorized access and ensures that it remains confidential even if the database is compromised.

Query tuning is an essential step in query performance testing. Query tuning involves optimizing the SQL queries to improve their performance and efficiency. It includes identifying and eliminating bottlenecks, rewriting queries for better execution plans, and optimizing indexes and database configurations to enhance query performance.

When the rollback plan fails, the testing team should immediately investigate the root cause of the failure. This involves analyzing logs, error messages, and system behavior to identify the technical issues preventing the rollback. Once the root cause is determined, appropriate corrective actions can be taken to address the underlying problems and ensure the effectiveness of the rollback process. Escalating to management may be necessary if the issue requires additional resources or expertise to resolve. Re-attempting rollback without understanding the root cause could lead to repeated failures and further complications in the data migration process.