Heikki Linnakangas wrote:
Tom Lane wrote:
Compared to what it currently takes to check the same tuple (a separate
index entry fetch and traversal to the heap page), this is already an
enormous performance improvement.

Though keep in mind that we kill index tuples as soon as they're deemed
to be dead. Nevertheless, I'm not very worried about the cost of
following the chain either. But that's something we can quite easily
measure if we want to.

I'm confused now. I though that pruning would be enough to shorten HOT-Chains -
because the root line pointer afterwards points directly to the first live
tuple. But we can *prune* (without actually defragmenting) without holding
a VACUUM-strength lock, right? Or did I get that wrong?

greetings, Florian Pflug

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