Manfred Koizar <mkoi-pg(at)aon(dot)at> writes:
> So it looks save to use this bit for marking dead tuples. Wouldn't it
> be even possible to simply reset LP_USED instead of setting
> LP_DELETED?
Mmmm ... I don't think so. That would cause the tuple to actually
disappear from the perspective of the index AM internals, which seems
like a bad idea. (For example, if another backend had an indexscan
stopped on that same tuple, it would fail to re-find its place when it
tried to continue the indexscan.)
> Yet another idea: set ItemIdData.lp_len = 0 for killed index tuples.
See above. This is *not* a substitute for vacuuming.
regards, tom lane