On 2023-11-27 11:29:48 +0530, Ashutosh Bapat wrote: > How do we ensure that we are not making unnecessary copies of Bitmapsets?
We don't - but that's not specific to this patch. Bitmapsets typically aren't very large, I doubt that it's a significant proportion of the memory usage. Adding refcounts or such would likely add more overhead than it'd save, both in time and memory. I am a bit worried about the maintainability of remove_rel_from_query() et al. Is there any infrastructure for detecting that some PlannerInfo field that needs updating wasn't updated? There's not even a note in PlannerInfo that documents that that needs to happen.