Re: PG 13 release notes, first draft

On Sat, May 9, 2020 at 11:16 AM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>
> On Tue, May 5, 2020 at 8:46 AM Bruce Momjian <bruce(at)momjian(dot)us> wrote:
> >
> > I have committed the first draft of the PG 13 release notes. You can
> > see them here:
> >
> > https://momjian.us/pgsql_docs/release-13.html
> >
>
> Thanks for the work. I was today going through the release notes and
> was wondering whether we should consider adding information about some
> other work done for PG13.
> 1. We have allowed an (auto)vacuum to display additional information
> about heap or index in case of an error in commit b61d161c14 [1].
> Now, in general, it might not be worth saying much about error
> information but I think this one could help users in case they have
> some corruption. For example, if one of the indexes on a relation has
> some corrupted data (due to bad hardware or some bug), it will let the
> user know the index information, and the user can take appropriate
> action like either Reindex or maybe drop and recreate the index to
> overcome the problem.
> 2. In the "Source Code" section, we can add information about
> infrastructure enhancement for parallelism. Basically, "Allow
> relation extension and page lock to conflict among parallel-group
> members" [2][3]. This will allow improving the parallelism further in
> many cases like (a) we can allow multiple workers to operate on a heap
> and index in a parallel vacuum, (b) we can allow parallel Inserts,
> etc.
>

One more observation:

Allow inserts to trigger autovacuum activity (Laurenz Albe, Darafei
Praliaskouski)
This new behavior allows pages to be set as all-visible, which then
allows index-only scans, ...

The above sentence sounds to mean that this feature allows index-only
scans in more number of cases after this feature. Is that what you
intend to say? If so, is that correct? Because I think this will
allow index-only scans to skip "Heap Fetches" in more cases.

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