Re: Questions/Observations related to Gist vacuum

Hi!

> 18 окт. 2019 г., в 13:21, Dilip Kumar <dilipbalaut(at)gmail(dot)com> написал(а):
>
> On Fri, Oct 18, 2019 at 10:55 AM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>>
>>
>> I think we can do it in general as adding some check for parallel
>> vacuum there will look bit hackish.
> I agree with that point.
> It is not clear if we get enough
>> benefit by keeping it for cleanup phase of the index as discussed in
>> emails above. Heikki, others, let us know if you don't agree here.
>
> I have prepared a first version of the patch. Currently, I am
> performing an empty page deletion for all the cases.

I've took a look into the patch, and cannot understand one simple thing...
We should not call gistvacuum_delete_empty_pages() for same gist_stats twice.
Another way once the function is called we should somehow update or zero empty_leaf_set.
Does this invariant hold in your patch?

Best regards, Andrey Borodin.