Thanks for the clarification Peter,
On 21/06/2022 08:46, Peter Geoghegan wrote:
>
>> But why the temp files are always on disk and not in RAM as other operations do?
> Why not?
Systems running on slow disks will probably suffer from workers writing temp files to disk.
> It is probably true that it would be better to use shared memory in
> the case where there is sufficient memory, but it's not all that
> significant compared to everything else that must happen at the same
> time. It's rarely the bottleneck. External sorts are often faster than
> internal sorts. That happens because they can be more CPU cache
> friendly, for reasons that aren't fundamental.
>
I would expect this behavior to be mentioned in the documentation.
regards,
fabio pardi