refactor: Expr::Exists to use a struct.

[QuenKar]

Which issue does this PR close?

Related to #2175 and #3807.

Rationale for this change

What changes are included in this PR?

Refactor Expr::Exists to a struct.

Are these changes tested?

Yes.

Are there any user-facing changes?

[QuenKar]

When I run cargo test, I met a question.

thread 'tpcds_logical_q64' has overflowed its stack
fatal runtime error: stack overflow
error: test failed, to rerun pass `-p datafusion --test tpcds_planning`

I found that this test used a lot of tables, and it says that stack overflow. How can I pass this test?

[jackwener]

When I run cargo test, I met a question.

thread 'tpcds_logical_q64' has overflowed its stack
fatal runtime error: stack overflow
error: test failed, to rerun pass `-p datafusion --test tpcds_planning`

I found that this test used a lot of tables, and it says that stack overflow. How can I pass this test?

You can ignore it, it's a known issue #6277

[jackwener]

Nice job, Thank you @QuenKar

find some problem

[jackwener]

I have resolved conflicts.
Thanks @QuenKar 's contribution.
LGTM

[QuenKar]

I have resolved conflicts. Thanks @QuenKar 's contribution. LGTM

Thank you!