I went through the README on HOT. That was really a nice and cool feature. Hats off to the person who thought about it. I have a couple of doubts about it.
a) In the README, there is a statement like this. In principle we could continue a HOT chain across pages, but this would destroy the desired property of being able to reclaim space with just page-local manipulations. Anyway, we don't want to have to chase through multiple heap pages to get from an index entry to the desired tuple, so it seems better to create a new index entry for the new tuple. I am especially interested in the case of continuing the HOT chain across pages. When we are actually reclaiming space, we should check the snapshot and reclaim it. If it is HOT updated, we will leave the top most tuple and take the rest. So then the top most tuple will remain always and any index scan now has to make read two heap pages to reach the target entry.Is this the only reason, it was left out? -- Thanks, Gokul. CertoSQL Project, Allied Solution Group. (www.alliedgroups.com)
