Re: Postgres 11 release notes - Mailing list pgsql-hackers

From Peter Geoghegan
Subject Re: Postgres 11 release notes
Date
Msg-id CAH2-Wz=gWUAFc-xDxkjBxNGuh2B7LVdEWXGjKDbdeK5P0=H14w@mail.gmail.com
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In response to Re: Postgres 11 release notes  (Andres Freund <andres@anarazel.de>)
Responses Re: Postgres 11 release notes  (Peter Geoghegan <pg@bowt.ie>)
Re: Postgres 11 release notes  (Bruce Momjian <bruce@momjian.us>)
List pgsql-hackers
On Fri, May 11, 2018 at 12:04 PM, Andres Freund <andres@anarazel.de> wrote:
> I don't think the table being 'append-only' is necessary?  Nor does it
> have to be a manual vacuum. And 'needless index scan' sounds less than
> it is/was, namely a full scan of the index. Perhaps something like:
>
>   Allow vacuum to skip doing a full scan of btree indexes after VACUUM,
>   if not necessary.
>
> or something like that?

I suggest "Allow vacuuming to avoid full index scans for indexes when
there are no dead tuples found in a table. Where necessary, the
behavior can be adjusted via the new configuration parameter
vacuum_cleanup_index_scale_factor."

Also:

* "Allow indexes to be built in parallel" should specify that it only
works for B-Tree index builds.

* Suggest replacement sort item be phrased as: "Remove the
configuration parameter replacement_sort_tuples. <newline> The
replacement selection sort algorithm is no longer used."

-- 
Peter Geoghegan


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