Re: Questions/Observations related to Gist vacuum

On Wed, Oct 16, 2019 at 7:21 PM Heikki Linnakangas <hlinnaka@iki.fi> wrote:
>
> On 16 October 2019 12:57:03 CEST, Amit Kapila <amit.kapila16@gmail.com> wrote:
> >On Tue, Oct 15, 2019 at 7:13 PM Heikki Linnakangas <hlinnaka@iki.fi>
> >wrote:
> >> All things
> >> considered, I'm not sure which is better.
> >
> >Yeah, this is a tough call to make, but if we can allow it to delete
> >the pages in bulkdelete conditionally for parallel vacuum workers,
> >then it would be better.
>
> Yeah, if it's needed for parallel vacuum, maybe that tips the scale.
>

makes sense.  I think we can write a patch for it and prepare the
parallel vacuum patch on top of it.  Once the parallel vacuum is in a
committable shape, we can commit the gist-index related patch first
followed by parallel vacuum patch.

> Hopefully, multi-pass vacuums are rare in practice. And we should lift the current 1 GB limit on the dead TID array,
replacingit with something more compact and expandable, to make multi-pass vacuums even more rare. So I don't think we
needto jump through many hoops to optimize the multi-pass case. 
>

Yeah, that will be a good improvement.

--
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com