Horton

Re: On disable_cost

David Rowley <dgrowleyml@gmail.com>

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From: David Rowley <dgrowleyml@gmail.com>
To: Laurenz Albe <laurenz.albe@cybertec.at>
Cc: Alena Rybakina <a.rybakina@postgrespro.ru>, Robert Haas <robertmhaas@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>, Heikki Linnakangas <hlinnaka@iki.fi>, Peter Geoghegan <pg@bowt.ie>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2024-10-11T07:45:08Z
Lists: pgsql-hackers

Attachments

On Fri, 11 Oct 2024 at 19:44, Laurenz Albe <laurenz.albe@cybertec.at> wrote:
>
> On Fri, 2024-10-11 at 17:24 +1300, David Rowley wrote:
> > I've now pushed this change and will look at the docs now.
>
> Thanks you for taking care of that!

I've attached a patch for this. It's very similar to your patch and in
the same location, just the wording is slightly different. I also
opted to use a table that exists in the regression database as the top
of the page mentions "Examples in this section are drawn from the
regression test database".

Attached in patch form and with compiled HTML.

David

Commits

  1. Doc: add detail about EXPLAIN's "Disabled" property

  2. Adjust EXPLAIN's output for disabled nodes

  3. Fix order of parameters in a cost_sort call

  4. Show number of disabled nodes in EXPLAIN ANALYZE output.

  5. Treat number of disabled nodes in a path as a separate cost metric.

  6. Remove grotty use of disable_cost for TID scan plans.