Re: file cloning in pg_upgrade and CREATE DATABASE

On 17.07.18 08:58, Michael Paquier wrote:
> Hm... I am wondering if we actually want the "auto" mode where we make
> the option smarter automatically. I am afraid of users trying to use it
> and being surprised that there is no gain while they expected some. I
> would rather switch that to an on/off switch, which defaults to "off",
> or simply what is available now. huge_pages=try was a bad idea as the
> result is not deterministic, so I would not have more of that...

Why do you think that was a bad idea? Doing the best possible job by
default without requiring explicit configuration in each case seems like
an attractive feature.

> Putting CloneFile and check_reflink in a location that other frontend
> binaries could use would be nice, like pg_rewind.

This could be done in subsequent patches, but the previous iteration of
this patch for CREATE DATABASE integration already showed that each of
those cases needs separate consideration.

--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services