Re: GIN data corruption bug(s) in 9.6devel

On Fri, Apr 22, 2016 at 2:20 PM, Jeff Janes <jeff(dot)janes(at)gmail(dot)com> wrote:
>> Check my reasoning: In version 4 I added a remebering of tail of pending
>> list into blknoFinish variable. And when we read page which was a tail on
>> cleanup start then we sets cleanupFinish variable and after cleaning that
>> page we will stop further cleanup. Any insert caused during cleanup will be
>> placed after blknoFinish (corner case: in that page), so, vacuum should not
>> miss tuples marked as deleted.
>
> Yes, I agree with the correctness of v4. But I do wonder if we should
> use that early stopping for vacuum and gin_clean_pending_list, rather
> than just using it for user backends. While I think correctness
> allows it to stop early, since these routines are explicitly about
> cleaning things up it seems like they should volunteer to clean the
> whole thing.

Not to hold anyone's feet to the fire, but we are running out of time
before beta1, and this seems to be one of the more serious outstanding
issues. I'd rather not release beta1 with known data corruption bugs,
but that means either fixing whatever is broken here or reverting the
commit that caused or revealed the problem pretty soon.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
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