The blog post explores the trade-offs between physical and logical data isolation methods in multitenant applications, particularly focusing on how Highlight.io, an open-source monitoring platform, addresses these challenges using a multitenant ClickHouse cluster. Physical isolation involves maintaining separate infrastructure for each tenant, which can be resource-intensive, while logical isolation uses shared infrastructure with application-level access restrictions, which can be prone to errors and vulnerabilities. Highlight.io employs ClickHouse row policies to enforce logical data isolation, creating roles and row policies for tenants to ensure secure access to data without the complexity of managing numerous roles and policies. They implemented a hybrid approach that leverages ClickHouse's row policies and custom settings, using a context object in the clickhouse-go Golang driver to enhance security against SQL injection and ensure tenant-level isolation. This method reduces error risk, avoids the overhead of creating extensive access control objects, and provides a more secure solution for managing data in a multitenant environment.