Re: Is there a way (except from server logs) to know the kind of on-going/last checkpoint?

At Sat, 29 Jan 2022 00:10:19 +0800, Julien Rouhaud <rjuju123@gmail.com> wrote in 
> On Fri, Jan 28, 2022 at 08:21:52PM +0530, Bharath Rupireddy wrote:
> > > Also, you still didn't fix the possible flag upgrade issue.
> 
> Unless I'm missing something that's an issue that you still haven't addressed
> or explained why it's not a problem?

As Bharath said, pg_upgreade reads a part of old cluster's controldata
that is needed to check compatibility so I agree that we don't have
flag upgrade issue I mentioned.

> > > Why are you defining CHECKPOINT_KIND_TEXT_LENGTH twice?  You
> > > should just define it in some sensible header used by both files, or better
> > > have a new function to take care of that rather than having the code
> > > duplicated.
> > 
> > Yeah, added the macro in pg_control.h. I also wanted to have a common
> > function to get checkpoint kind text and place it in
> > controldata_utils.c, but it doesn't have xlog.h included, so no
> > checkpoint flags there, hence I refrained from the common function
> > idea.
> 
> That's a bit annoying, I'm not sure what's best to do here.

I misunderstood that the size is restricted to 8k but it is really 512
bytes as Andres pointed.  So we don't add it at least as a text.  This
means pg_controldata need to translate the flags into human-readable
text but, to be clear, I still don't think its usefull in the control
data.

regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center