Signed-off-by: Bugen Zhao [email protected]I hereby agree to the terms of the RisingWave Labs, Inc. Contributor License Agreement.

What's changed and what's your intention?

Follow-up of #16279. Based on some actual queries provided by users, this PR adopts fearless recursion to more places to provide better support for complicated plan in optimizer, including:

• Expression visitor / rewriter
• Plan visitor / rewriter

The theory behind why this will work by only touching the optimizer code may be that, the final physical plan and expression tree executed on the compute nodes could be less complex than what we have to handle in the optimizer, thus requiring less stack depth. This is further because...

• we have common sub-expression elimination
• we will cut the plan tree into fragments when executing

However, this still cannot cover those most complicated queries, which will overflows the stack even when calling the compiler-generated Clone impl. The only workaround is to set RUST_STACK_SIZE in that case.

Checklist

• I have written necessary rustdoc comments
• I have added necessary unit tests and integration tests
• All checks passed in ./risedev check (or alias, ./risedev c)

Documentation

• My PR needs documentation updates. (Please use the Release note section below to summarize the impact on users)

Release note

If this PR includes changes that directly affect users or other significant modifications relevant to the community, kindly draft a release note to provide a concise summary of these changes. Please prioritize highlighting the impact these changes will have on users.