Re: [GENERAL] gin index trouble

On 10/30/2017 10:56 AM, Peter Geoghegan wrote:
> On Mon, Oct 30, 2017 at 9:45 AM, Rob Sargent <robjsargent@gmail.com> wrote:
>> Peter, you beat me to the punch.  I was just about to say "Having read the
>> referenced message I thought I would add that we never delete from this
>> table."  In this particular case it was written to record by record, in a
>> previous execution and at the time of the error it was only being read.  (In
>> case you've been following, the failed execution would have added ~1M
>> "segments", each which references an entry in the gin'd table "probandsets"
>> - but like a rookie I'm looking up each probandset(2^16) individually.
>> Re-working that NOW.)
> It's not surprising that only a SELECT statement could see this
> problem. I guess that it's possible that only page deletions used for
> the pending list are involved here.
>
> I'm not sure how reliably you can recreate the problem, but if it
> doesn't take too long then it would be worth seeing what effect
> turning off the FASTUPDATE storage parameter for the GIN index has.
> That could prevent the problem from recurring, and would support my
> theory about what's up here. (It wouldn't fix the corruption, though.)
>
> Of course, what I'd much prefer is a self-contained test case. But if
> you can't manage that, or if reproducing the issue takes hours, then
> this simpler experiment might be worthwhile.
>
I can reload the gin'd table repeatedly in a dev environment. Does 
select * from <table> order by <gin'd column> expose the corruption or 
does the load itself necessarily fail at the moment of corruption?



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