Better JOIN ON Keys Extraction #6131 (artem Zuikov)

Why it matters

This feature enhances ClickHouse's ability to correctly identify and handle join keys in JOIN ON clauses, reducing errors and improving query performance when joining tables. It simplifies the process of optimizing join queries and ensures more reliable execution.

How to use it

Users do not need to change any syntax; the improvement is applied internally by ClickHouse. Simply write JOIN queries with ON clauses as usual, and the system will leverage the enhanced key extraction automatically.