From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Andres Freund <andres@anarazel.de>
Cc: Simon Riggs <simon@2ndquadrant.com>
Cc: Pg Hackers <pgsql-hackers@lists.postgresql.org>
Cc: David Fetter <david@fetter.org>
Cc: Rahila Syed <rahila.syed@2ndquadrant.com>
Cc: Pavan Deolasee <pavan.deolasee@gmail.com>
Cc: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
Subject: Re: monitoring CREATE INDEX [CONCURRENTLY]
Date: Sat, 30 Mar 2019 02:09:47 -0300
Message-ID: <20190330050947.GA7954@alvherre.pgsql> (raw)
In-Reply-To: <CA+Tgmoa8yW__yGv87-_K=BKt-j0cNWGBYvY=c_wi=yhdE6KDFw@mail.gmail.com>
On 2019-Mar-29, Robert Haas wrote:
> On Fri, Mar 29, 2019 at 3:28 PM Alvaro Herrera <alvherre@2ndquadrant.com> wrote:
> > Maybe we can consider using dynamic shmem for that, and include a
> > pointer to it in the fixed-size chunk. (It's a bit too late to be
> > writing this code, mind; I'm just proposing this for a future
> > improvement.)
>
> Sounds expensive. We don't want to spend a lot of energy pushing out
> progress reports which, often enough, nobody will ever examine. I
> designed the current system as I did to make it cheap.
Well, I'm not proposing this for things that would change more than once
or a very limited number of times during one command; certainly not once
per tuple or per block like other metrics do. The examples I mentioned
are once per command (eg., list of OIDs of partitions to process) or
list of PIDs to wait for, which we wouldn't modify it once set for each
waiting cycle (three times for CREATE INDEX CONCURRENTLY, five times for
REINDEX CONCURRENTLY).
> Adding DSM in there would open up lots of exciting new failure
> possibilities and significantly increase the overhead. And probably
> add quite a bit of code complexity, too.
Yeah, that's true.
Anyway, I'm not intending to tackle this for the time being.
--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-hackers@postgresql.org
Cc: alvherre@2ndquadrant.com, robertmhaas@gmail.com, andres@anarazel.de, simon@2ndquadrant.com, pgsql-hackers@lists.postgresql.org, david@fetter.org, rahila.syed@2ndquadrant.com, pavan.deolasee@gmail.com, Langote_Amit_f8@lab.ntt.co.jp
Subject: Re: monitoring CREATE INDEX [CONCURRENTLY]
In-Reply-To: <20190330050947.GA7954@alvherre.pgsql>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox