Horton

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

Fujii Masao <masao.fujii@oss.nttdata.com>

View thread View on postgr.es
From: Fujii Masao <masao.fujii@oss.nttdata.com>
To: Nathan Bossart <nathandbossart@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>
Cc: Jelte Fennema-Nio <postgres@jeltef.nl>, Robert Haas <robertmhaas@gmail.com>, pgsql-hackers@lists.postgresql.org
Date: 2024-07-10T16:07:51Z
Lists: pgsql-hackers 

On 2024/07/11 0:44, Nathan Bossart wrote:
> On Wed, Jul 10, 2024 at 11:11:13AM -0400, Tom Lane wrote:
>> Please, no.  We went through a ton of permutations of that kind of
>> idea years ago, when it first became totally clear that cross-checks
>> between GUCs do not work nicely if implemented in check_hooks.
>> (You can find all the things we tried in the commit log, although
>> I don't recall exactly when.)
> 
> Understood.
> 
>> A counter-example for what you just
>> said is when a configuration file like the above is loaded after
>> postmaster start.
> 
> I haven't tested it, but from skimming around the code, it looks like
> ProcessConfigFileInternal() would deduplicate any previous entries in the
> file prior to applying the values and running the check hooks.  Else,
> reloading a configuration file with multiple startup-only GUC entries could
> fail, even without bogus GUC check hooks.

Yeah, I'm thinking the same.

Regards,

-- 
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION

Commits

  1. Do not summarize WAL if generated with wal_level=minimal.

  2. Revert "Auto-tune effective_cache size to be 4x shared buffers"

  3. Un-break ecpg test suite under --disable-integer-datetimes.

  4. Again fix initialization of auto-tuned effective_cache_size.

  5. Code review for auto-tuned effective_cache_size.

  6. Auto-tune effective_cache size to be 4x shared buffers