Robert Haas <robertmh...@gmail.com> writes: > On Mon, Nov 21, 2022 at 12:38 PM Tom Lane <t...@sss.pgh.pa.us> wrote: >> What it's restricting is the number of heap page fetches, which >> might be good enough. We don't have a lot of visibility here >> into how many index pages were scanned before returning the next >> not-dead index entry, so I'm not sure how hard it'd be to do better.
> Oh. That's really sad. Because I think the whole problem here is that > the number of dead index entries can be huge. If they're *actually* dead, we have enough mitigations in place I think, as explained by the long comment in get_actual_variable_endpoint. The problem here is with still-visible-to-somebody tuples. At least, Jakub's test case sets it up that way. regards, tom lane