v.25.5Improvement

Add a query level

Add a query level setting to enable delta-kernel-rs: allow_experimental_delta_kernel_rs. #79418 (Kseniia Sumarokova).
Introduces a query-level setting allow_experimental_delta_kernel_rs to enable the experimental delta-kernel-rs feature in ClickHouse.

Why it matters

This feature allows users to selectively enable the experimental delta-kernel-rs implementation for specific queries. It facilitates testing and gradual adoption of the new delta kernel, which may improve query performance or add new capabilities.

How to use it

To use this feature, set the query setting allow_experimental_delta_kernel_rs to 1 or true in your query, for example:

SELECT * FROM table SETTINGS allow_experimental_delta_kernel_rs = 1;