Date: Wed, 20 May 2020 19:30:18 -0400
From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: "Jonathan S. Katz" <jkatz@postgresql.org>
Cc: PostgreSQL Advocacy <pgsql-advocacy@lists.postgresql.org>
Subject: Re: PostgreSQL 13 Beta 1 Release Announcement Draft
Message-ID: <20200520233018.GA32614@alvherre.pgsql>
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Hello, sorry for the timing on this, but here's some feedback.

On 2020-May-20, Jonathan S. Katz wrote:

> PostgreSQL 13 introduces many features and improvements to the world's most
> advanced open source database. The following is just a small sample of new
> features introduced into this latest version of PostgreSQL.

"A small sample" suggests to me that there are other equally important
features that you did not list, in a somewhat random way.  I doubt
that's true; as a user, I would expect you to list the most important
changes.  I would use the phrase "The following are the most visible
improvements" or some such.

> PostgreSQL 13 adds incremental sorting, which accelerates sorting data when
> existing data in a query is already sorted.

I'm not sure this is very accurate.  I would say "incremental sorting,
which can take advantage of partially sorted data". (Could add more to
it, "when only a subset of the result set is needed", but that is
perhaps too many words).

> There are more improvements added to PostgreSQL's partitioning functionality in
> this release, including an increased number of cases where a
> "partitionwise join" (a join between matching partitions) can be used,

I'd say "A join between partitioned tables".  (The new feature precisely
is that the partition strategies don't have to match exactly anymore).

> One of the most anticipated features of PostgreSQL 13 is the ability for the
> `VACUUM` command to process indexes in parallel. This functionality can be
> accessed using the new `PARALLEL` option on the `VACUUM` command (or
> `--parallel` on `vacuumdb`), which allows you to specify the number of parallel
> workers to use for vacuuming indexes. Note that this does not work with the
> `FULL` option.

I feel this "Note" is unnecessary; VACUUM FULL is of fringe use anyway.
The phrase on incremental sorting above is better use of these extra
words, if you have a surplus.
 
> This release includes more ways to monitor actibity within a PostgreSQL
> database: PostgreSQL 13 can now track WAL usage statistics and the progress of
> streaming `pg_basebackup`s, and the progress of an `ANALYZE` command.
> `pg_basebackup` can also generate a manifest that can be used to verify the
> integrity of a backup using a new tool called `pg_verifybackup`.

In this monitoring paragraph I would add that it's possible to limit WAL
reserved by replication slots.  "It is now possible to limit the amount
of WAL space reserved by replication slots."

Thanks!

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services