ClickHouse version 25.9 introduces several new features, performance optimizations, and bug fixes, including automatic global join reordering, streaming for secondary indices, and a new text index. The global join reordering feature allows for more efficient execution of complex join operations by optimizing the order of joins based on the size of the tables involved, significantly improving query runtime and reducing memory usage. Additionally, the release enhances the performance of secondary indices by enabling streaming, which concurrently checks index entries while reading data, reducing startup delays and inefficiencies. The update also includes a new experimental text index for more efficient full-text search and several other improvements such as data lake support, a new arrayExcept function, and the ability to define boolean settings without specifying arguments. These advancements contribute to making ClickHouse more efficient and versatile for complex data processing tasks.