Re: pg_combinebackup --clone doesn't work

On 21.06.24 18:10, Tomas Vondra wrote:
> On 6/21/24 00:07, Tomas Vondra wrote:
>> Here's a fix adding the missing headers to pg_combinebackup, and fixing
>> some compile-time issues in the ifdef-ed block.
>>
>> I've done some basic manual testing today - I plan to test this a bit
>> more tomorrow, and I'll also look at integrating this into the existing
>> tests.
>>
>
> Here's a bit more complete / cleaned patch, adding the testing changes
> in separate parts.
>
> 0001 adds the missing headers / fixes the now-accessible code a bit
>
> 0002 adds the --copy option for consistency with pg_upgrade

This looks good.

> 0003 adds the PG_TEST_PG_COMBINEBACKUP_MODE, so that we can override the
> copy method for tests

I had imagined that we combine PG_TEST_PG_UPGRADE_MODE and this new one
into one setting. But maybe that's something to consider with less time
pressure for PG18.

> I believe 0001-0003 are likely non-controversial, although if someone
> could take a look at the Perl in 0003 that'd be nice. Also, 0002 seems
> nice not only because of consistency with pg_upgrade, but it also makes
> 0003 easier as we don't need to special-case the default mode etc.

Right, that was one of the reasons.

> 0004 tweaks two of the Cirrus CI tasks to use --clone/--copy-file-range

> I'm not sure about 0004 - I initially did this mostly to check we have
> the right headers on other platforms, but not sure we want to actually
> do this. Or maybe we want to test a different combination (e.g. also
> test the --clone on Linux)?

It's tricky to find the right balance here. We had to figure this out
for pg_upgrade as well. I think your solution is good, and we should
also add test coverage for pg_upgrade --copy-file-range in the same
place, I think.