v.20.5Improvement

Improve multiple joins rewriter logic to fix unknown columns error for lambda aliases

Improve multiple_joins_rewriter_version=2 logic. Fix unknown columns error for lambda aliases. #11587 (Artem Zuikov).
Improved the multiple_joins_rewriter_version=2 logic to fix unknown columns errors occurring with lambda aliases in queries.

Why it matters

This feature addresses a bug where using lambda aliases in queries caused unknown columns errors when multiple_joins_rewriter_version=2 was enabled. By fixing this, it ensures more reliable query rewriting and execution involving multiple joins and lambdas, enhancing query stability and correctness.

How to use it

To benefit from this fix, users should enable multiple_joins_rewriter_version=2 in their session or query settings. The improved logic now correctly handles lambda aliases without causing unknown column errors.