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

>> 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
Interesting, I've missed this possible option

> 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.

I believe that autovacuum should not require guaranteed full clean up, only
vacuum and gin_clean_pending_list() should do that. In all other cases it should
stop early to prevent possible infinite cleanup. Patch attached.

--
Teodor Sigaev E-mail: teodor(at)sigaev(dot)ru
WWW: http://www.sigaev.ru/