Data cleansing is about rectifying inconsistencies or anomalies in the data, ensuring data quality and integrity for accurate analysis and decision-making.

SQL injection attacks occur when an attacker inserts malicious SQL code into input fields, exploiting vulnerabilities in the application's SQL query construction. Escaping special characters is a technique used to neutralize the effect of these characters, preventing them from being interpreted as part of the SQL query. This helps to ensure the integrity and security of the database.

Regulatory standards for databases are typically defined by government agencies. These standards may vary depending on the industry and location, and organizations must ensure compliance with the relevant regulations to avoid legal and financial consequences.

ETL testing tools often include data profiling capabilities, allowing testers to analyze the data and identify potential quality issues such as inconsistencies, duplicates, or missing values. Profiling helps in understanding the data distribution and its characteristics, facilitating effective testing and validation of ETL processes.

SQL injection testing involves probing a system with malicious SQL queries to identify vulnerabilities. It is critical in SQL query testing to prevent attackers from exploiting vulnerabilities to gain unauthorized access to databases or manipulate data.

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.

The SQL statement commonly used for testing the integrity of primary keys in a table is "ALTER TABLE ... ADD CONSTRAINT ... PRIMARY KEY". This statement is used to add a primary key constraint to a table, ensuring that the specified column(s) uniquely identify each row and enforcing data integrity. By adding a primary key constraint, it becomes impossible to insert duplicate or null values into the primary key column(s), thus maintaining the integrity of the data.

Common signs of SQL injection vulnerability include the presence of unsanitized user input directly concatenated into SQL queries, error messages that reveal database structure or query information, and the absence of input validation mechanisms. These indicators suggest that the system does not adequately sanitize and validate user input, making it vulnerable to SQL injection attacks.

In a blind SQL injection attack, attackers may exploit error messages or use comments to gather information. However, a common technique is using database metadata to understand the database structure.