Re: Add a GUC check hook to ensure summarize_wal cannot be enabled when wal_level is minimal

On Wed, Jul 10, 2024 at 04:29:14PM +0200, Jelte Fennema-Nio wrote:
> On Wed, 10 Jul 2024 at 16:18, Nathan Bossart <nathandbossart@gmail.com> wrote:
>> Yeah.  I initially thought this patch might be okay, at least as a stopgap,
>> but Jelte pointed out a case where it doesn't work, namely when you have
>> something like the following in the config file:
>>
>>         wal_level = 'minimal'
>>         summarize_wal = 'true'
>>         wal_level = 'logical'
> 
> I think that issue can be solved fairly easily by making the guc
> check_hook always pass during postmaster startup (by e.g. checking
> pmState), and relying on the previous startup check instead during
> startup.

I was actually just thinking about doing something similar in a different
thread [0].  Do we actually need to look at pmState?  Or could we just skip
it if the context is <= PGC_S_ARGV?

[0] https://postgr.es/m/Zow-DBaDY2IzAzA2%40nathan

-- 
nathan