Hi all, I came across this JIRA and am not sure what its status is. The original proposal in the bug looks reasonable to me. We currently propagate importance improvement through a depth-first model, which could result in stack overflow if the memo is very big and very deep. Change it into a breadth-first algorithm seems reasonable and straightforward.
The JIRA also mentions multiple places in the code (such as RelMdRowCount.java) using hack to work around CALCITE 1048. But that doesn’t seem to relate to what this JIRA intends to do. I am thinking we can scope down this to just use breadth-first cost propagation and then we can have separate issues logged for removing the hacks in RelMdRowCount. Any thoughts? Thanks.
