Re: Temporary files usage in explain - Mailing list pgsql-general

From David Rowley
Subject Re: Temporary files usage in explain
Date
Msg-id CAApHDvqh33cFnVzR-JWGEbSBQfuOR3_2LbGyD6mTr_+AzHnVyg@mail.gmail.com
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In response to Temporary files usage in explain  (Matteo Bonardi <mbona92@gmail.com>)
Responses Re: Temporary files usage in explain
List pgsql-general
On Tue, 27 Apr 2021 at 21:15, Matteo Bonardi <mbona92@gmail.com> wrote:
> Explain plan: https://explain.depesz.com/s/BXGT
>
> Usually I'm looking for "external merge Disk" to see temp files usage but, in this case, the only reference to that
is299,368kB in the last but one node of explain.
 
> Can anyone help me understand where the 45GB are in that explain?

If you do EXPLAIN (ANALYZE, BUFFERS) you might find that the recursive
CTE is writing the rest of them out.  Something like "temp written =
", likely around 5 million or so, I imagine.

David



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