Date: Wed, 1 Jul 2020 16:25:35 -0400
From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Bruce Momjian <bruce@momjian.us>
Cc: David Steele <david@pgmasters.net>,
	Fujii Masao <masao.fujii@oss.nttdata.com>,
	pgsql-hackers@postgresql.org
Subject: Re: max_slot_wal_keep_size and wal_keep_segments
Message-ID: <20200701202535.GA26854@alvherre.pgsql>
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On 2020-Jul-01, Bruce Momjian wrote:

> We have the following wal*size GUC settings:
> 
> 	SELECT name FROM pg_settings WHERE name LIKE '%wal%size%';
> 	          name
> 	------------------------
> 	 max_slot_wal_keep_size
> 	 max_wal_size
> 	 min_wal_size
> 	 wal_block_size
> 	 wal_segment_size
> 
> Does wal_keep_size make sense here?

I think it does.  What do you think?

Are you suggesting that "keep_wal_size" is better, since it's more in
line with min/max?  I lean towards no.

(I think it's okay to conceptually separate these three options from
wal_block_size, since that's a compile time option and thus it's an
introspective GUC rather than actual configuration, but as I recall that
argument does not hold for wal_segment_size. But at one point, even that
one was an introspective GUC too.)

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services