At Fri, 12 Jan 2024 11:28:09 -0500, Robert Haas <robertmh...@gmail.com> wrote in > However, I wonder whether this whole area is in need of a bigger > rethink. There seem to be a number of situations in which the split > into xip and subxip arrays is not very convenient, and also some > situations where it's quite important. Sometimes we want to record > what's committed, and sometimes what isn't. It's all a bit messy and > inconsistent. The necessity of limiting snapshot size is annoying, > too. I have no real idea what can be done about all of this, but what > strikes me is that the current system has grown up incrementally: we > started with a data structure designed for the original use case, and > now by gradually adding new use cases things have gotten complicated. > If we were designing things over from scratch, maybe we'd do it > differently and end up with something less messy. And maybe someone > can imagine a redesign that is likewise less messy. > > But on the other hand, maybe not. Perhaps we can't really do any > better than what we have. Then the question becomes whether this case > is important enough to justify additional code complexity. I don't > think I've personally seen users run into this problem so I have no > special reason to think that it's important, but if it's causing > issues for other people then maybe it is.
Thank you for the deep insights. I have understood your points. As I can't think of any further simple modifications on this line, I will withdraw this CF entry. At the moment, I also lack a fundamental, comprehensive solution, but should if I or anyone else come up with such a solution in the future, I believe it would worth a separate discussion. regards. -- Kyotaro Horiguchi NTT Open Source Software Center
