> Looking at the discussion where the feature was added, I think changing the > EXPLAIN just wasn't considered.
I think this is an oversight. It is very useful to have this on EXPLAIN. > The attached patch adds "avoided" to "exact" and "lossy" as a category > under "Heap Blocks". It took me a while to figure out what those names mean. "unfetched", as you call it on the code, may be more descriptive than "avoided" for the new label. However I think the other two are more confusing. It may be a good idea to change them together with this. > I think the name of the node should also be changed to "Bitmap Only Heap > Scan", but I didn't implement that as adding another NodeTag looks like a > lot of tedious error prone work to do before getting feedback on whether > the change is desirable in the first place, or the correct approach. I am not sure about this part. In my opinion it may have been easier to explain to users if "Index Only Scan" had not been separate but "Index Scan" optimization.