Horton

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

Nathan Bossart <nathandbossart@gmail.com>

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From: Nathan Bossart <nathandbossart@gmail.com>
To: Jelte Fennema-Nio <postgres@jeltef.nl>
Cc: Robert Haas <robertmhaas@gmail.com>, Fujii Masao <masao.fujii@oss.nttdata.com>, pgsql-hackers@lists.postgresql.org
Date: 2024-07-10T14:46:41Z
Lists: pgsql-hackers 
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

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