Andrew Lamb

FYI @Lordworms I think this will be a pretty challenging task Also, @peter-toth has an outstanding substantial change to TreeNode APIs here: https://github.com/apache/arrow-datafusion/pull/8891 which you should be aware of.

> @alamb I'm thinking of introducing CommutativeExpr that specialize these kind of query to make them possible to transform iteratively. What do you think about this? I think that sounds...

> we could restrict the minimum elements of CommutativeExpr to 3. That could make sense My biggest concern with this proposal is its potential impact on backwards compatibility / causing...

> Otherwise we should count the transformation and raise the error. I recommend we start with the error (to avoid a stack overflow) and then if someone comes with a...

Here is how the recursion guard is implemented in sqlparser: https://github.com/sqlparser-rs/sqlparser-rs/blob/f9ab8dcc27fd2d55030b9c5fa71e41d5c08dd601/src/parser/mod.rs#L67-L127 And then at the start of each major statement, this gets called: https://github.com/sqlparser-rs/sqlparser-rs/blob/f9ab8dcc27fd2d55030b9c5fa71e41d5c08dd601/src/parser/mod.rs#L469-L470 So I don't think we would...

I evaluated stacker as part of sqlparser and I thought it was doing some too crazy stuff that made it hard to use in embedded / wasm environments. Maybe that...

Thank you all for working on this

I will try and find time to review this tomorrow. THank you @markusa380

I plan to review this tomorrow morning

Marking as draft as I think this PR is no longer waiting on feedback. Please mark it as ready for review when it is ready for another look