Consider calling a function in OPL or KQL like my_func(severity_text, attributes{"x"])

In these cases, the severity_text would have the "row order" of the root record batch, where attributes["x"] would have the "row order" of however the parent_ids were sorted in rows where key == "x".

by "row order" here, I mean the logical signal (e.g. log, span, etc.) represented by each row.

Currently the columnar query engine doesn't support this and will just return an error. We should fix this.