DB2 ensures data integrity through various mechanisms such as referential integrity, constraints, and data validation rules. Referential integrity constraints enforce relationships between tables to maintain data consistency, while constraints and validation rules define permissible data values and ensure data accuracy. By adhering to these principles, DB2 maintains the integrity and reliability of the stored data. 

Stored procedures in DB2 are commonly used to encapsulate business logic. Business logic refers to the rules and processes that govern the manipulation and management of data within an application. This can include calculations, validations, and other operations. 

The INSERT INTO statement adds new records (rows) to a table in a database. It is used to insert a new row of data into a specified table with specified values for each column. 

IBM Data Studio is designed to assist developers in developing applications for DB2 databases. It provides tools and features for writing and debugging SQL queries, designing and modifying database schemas, monitoring database performance, and optimizing queries. Hence, it enhances developers' productivity by providing a comprehensive environment for all stages of application development, from design to deployment. 

High cardinality columns in indexes in DB2 require special storage considerations. High cardinality columns contain many unique values, which may lead to increased storage requirements and indexing overhead. 

Data compression in DB2 works by identifying and removing redundant information within the dataset. This can include eliminating duplicate records, reducing unused space, or removing any unnecessary data that might be present, ultimately leading to a reduction in the overall size of the data stored in the database. 

Scrollable cursors in DB2 offer the advantage of fetching rows in both forward and backward directions. This is useful when navigating through large result sets, as it enables efficient data retrieval and manipulation. By using a scrollable cursor, developers can easily move back and forth within the result set without re-executing the query. This feature enhances application performance and user experience, especially in scenarios where users need to browse through extensive data sets. 

Enabling monitoring tools to capture SQL performance metrics allows the DB2 administrator to identify poorly performing queries during peak hours. These tools can provide insights into various metrics such as execution time, I/O operations, and locking behavior, enabling the administrator to pinpoint the cause of slow query performance. Increasing hardware resources or restarting the DB2 instance may provide temporary relief but may not address the root cause of the issue. Disabling unnecessary applications can reduce system load but may not directly address SQL performance concerns. 

Troubleshooting DB2 installation errors often involves examining log files generated during the installation process. Log files contain valuable information about errors, warnings, and other diagnostic messages, aiding in identifying and resolving installation issues. 

In DB2, XML or JSON format can store any structured data, including textual, numerical, or binary data. This flexibility allows for versatile data storage and retrieval.