Re: Writing WAL files

On 10/4/20 10:30 AM, Robert Inder wrote:
> 
> 
> On Sun, 4 Oct 2020 at 18:01, Adrian Klaver <adrian.klaver@aklaver.com 
> <mailto:adrian.klaver@aklaver.com>> wrote:
> 
>     On 10/4/20 9:54 AM, Robert Inder wrote:
>      > I am moving a database from PSQL 9 (!) on CentOS 6 to PSQL 12 on
>     CentOS 7
> 
>     It would help to know what the x in 9.x is? Before version 10 of
>     Postgres, the second number denoted a major version.
> 
> 
> 9.4.
> Moving to 12.4.

Well I'm going to say it has to do with this:

https://www.postgresql.org/docs/10/release-10.html

E.15.3.1.9.1. Write-Ahead Log (WAL)
Prevent unnecessary checkpoints and WAL archiving on otherwise-idle 
systems (Michael Paquier)

Because that is when this:

". (Increasing checkpoint_timeout will reduce unnecessary checkpoints on 
an idle system.)"

disappeared from the archive_timeout docs:

https://www.postgresql.org/docs/9.6/runtime-config-wal.html

vs

https://www.postgresql.org/docs/10/runtime-config-wal.html

Someone else will have to fill in the details.


-- 
Adrian Klaver
adrian.klaver@aklaver.com