Re: max_slot_wal_keep_size and wal_keep_segments

On Wed, Jul  1, 2020 at 04:25:35PM -0400, Alvaro Herrera wrote:
> 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.

No, I am more just asking since I saw wal_keep_size as a special version
of wal_size.  I don't have a firm opinion.

> 
> (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.)

Yep, just asking.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EnterpriseDB                             https://enterprisedb.com

  The usefulness of a cup is in its emptiness, Bruce Lee