The article says the benefit of O2N is there's no need to immediately update indexes, but then goes on to say postgres updates the indexes anyway! So is there actually any advantage to O2N at all?
If all table pages exist in memory and you are using cooperative GC, then O2N can be preferable. As workers scan version chains, they can clean up dead tuples without taking additional locks.
Good question! Also they point out that famous Uber article erroneously mentions write amplification caused by what they thought was N2O. IDK if write amplification is real or not. But if it is really O2N then there is no apparent reason for write amplification and entire Uber article might had been based on the wrong premise.
That article was just wondering pain bad, written by someone who was obviously a beginner to PostgreSQL and did not understsand the issue he was seeing.
Yes, there are real issues but that article should be ignored.