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

Nathan Bossart <nathandbossart@gmail.com>

From: Nathan Bossart <nathandbossart@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Jelte Fennema-Nio <postgres@jeltef.nl>, Robert Haas <robertmhaas@gmail.com>, Fujii Masao <masao.fujii@oss.nttdata.com>, pgsql-hackers@lists.postgresql.org
Date: 2024-07-11T20:42:26Z
Lists: pgsql-hackers
On Wed, Jul 10, 2024 at 01:41:41PM -0500, Nathan Bossart wrote:
> On Wed, Jul 10, 2024 at 11:11:13AM -0400, Tom Lane wrote:
>> 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.)
> 
> Do you remember the general timeframe or any of the GUCs involved?  I spent
> some time searching through the commit log and mailing lists, but I've thus
> far only found allusions to past bad experiences with such hooks.

Could it be the effective_cache_size work from 2013-2014?

	https://www.postgresql.org/message-id/flat/CAHyXU0weDECnab1pypNum-dWGwjso_XMTY8-NvvzRphzM2Hv5A%40mail.gmail.com
	https://www.postgresql.org/message-id/flat/CAMkU%3D1zTMNZsnUV6L7aMvfJZfzjKbzAtuML3N35wyYaia9MJAw%40mail.gmail.com
	https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=ee1e5662d8d8330726eaef7d3110cb7add24d058
	https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=2850896961994aa0993b9e2ed79a209750181b8a
	https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=af930e606a3217db3909029c6c3f8d003ba70920
	https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=a16d421ca4fc639929bc964b2585e8382cf16e33;hp=08c8e8962f56c23c6799178d52d3b31350a0708f

-- 
nathan



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