On Mon, Aug 16, 2021 at 06:12:54PM +0000, Bossart, Nathan wrote:
> I was looking at the --check switch for the postgres binary recently
> [0], and this sounds like something that might fit in nicely there.
> In the attached patch, --check will also check the control file if one
> exists.
This would not work on a running postmaster as CreateDataDirLockFile()
is called beforehand, but we want this capability, no?
Abusing a bootstrap option for this purpose does not look like a good
idea, to be honest, especially for something only used internally now
and undocumented, but we want to use something aimed at an external
use with some documentation. Using a separate switch would be more
adapted IMO. Also, I think that we should be careful with the read of
the control file to avoid false positives? We can rely on an atomic
read/write thanks to its maximum size of 512 bytes, but this looks
like a lot what has been done recently with postgres -C for runtime
GUCs, that *require* a read of the control file before grabbing the
values we are interested in.
--
Michael