Re: Re: PANIC: invalid index offnum: 186 when processing BRIN indexes in VACUUM

Hi,

On 11/02/2017 06:45 PM, Alvaro Herrera wrote:
> Tomas Vondra wrote:
>
>> Unfortunately, I think we still have a problem ... I've been wondering
>> if we end up producing correct indexes, so I've done a simple test.
>
> Here's a proposed patch that should fix this problem (and does, in my
> testing). Would you please give it a try?
>
> This patch changes two things:
>
> 1. in VACUUM or brin_summarize_new_values, we only process fully loaded
> ranges, and ignore the partial range at end of table.
>
> 2. when summarization is requested on the partial range at the end of a
> table, we acquire extension lock on the rel, then compute relation size
> and run summarization with the lock held. This guarantees that we don't
> miss any pages. This is bad for concurrency though, so it's only done
> in that specific scenario.
>

FWIW this patch fixes the issue for me - I can no longer reproduce the
bitmapscan vs. seqscan result discrepancies (even with the extra UPDATE
phase).

regards

--
Tomas Vondra http://www.2ndQuadrant.com
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