Add Setting to Preserve Identifier Names in Multiple JOINs

Why it matters

When performing multiple JOINs, ClickHouse rewrites identifier names which can cause confusion or issues in query readability and debugging. This setting allows users to keep the original identifier names intact, improving clarity and consistency in complex queries.

How to use it

Enable the feature by setting multiple_joins_try_to_keep_original_names to 1 (true) in your session or configuration file, for example:

SET multiple_joins_try_to_keep_original_names = 1;

This will keep the original identifier names during multiple JOINs rewrites.