Re: Allow ERROR from heap_prepare_freeze_tuple to be downgraded to WARNING

On Sat, Aug 29, 2020 at 4:36 AM Dilip Kumar <dilipbalaut(at)gmail(dot)com> wrote:
> One example is, suppose during vacuum, there are 2 tuples in the hot
> chain, and the xmin of the first tuple is corrupted (i.e. smaller
> than relfrozenxid). And the xmax of this tuple (which is same as the
> xmin of the second tuple) is smaller than the cutoff_xid while trying
> to freeze the tuple. As a result, it will freeze the second tuple but
> the first tuple will be left untouched.
>
> Now, if we come for the heap_hot_search_buffer, then the xmax of the
> first tuple will not match the xmin of the second tuple as we have
> frozen the second tuple. But, I feel this is easily fixable right? I
> mean instead of not doing anything to the corrupted tuple we can
> partially freeze it? I mean we can just leave the corrupted xid alone
> but mark the other xid as frozen if that is smaller then cutoff_xid.

That seems reasonable to me. Andres, what do you think?

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Robert Haas
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