Re: Can PostgreSQL create new WAL files instead of reusing old ones?

On Wed, Jun 20, 2018 at 1:35 PM, Jerry Jelinek <jerry(dot)jelinek(at)joyent(dot)com>
wrote:

> As Dave described in his original email on this topic, we'd like to avoid
> recycling WAL files since that can cause performance issues when we have a
> read-modify-write on a file that has dropped out of the cache.
>
> I have implemented a small change to allow WAL recycling to be disabled.
> It is visible at:
> https://cr.joyent.us/#/c/4263/
>
> I'd appreciate getting any feedback on this.
>
>
This looks so simple, yet so beneficial. Thanks for making it. Is there
some other mechanism that already cleans out the old unneeded WAL files? I
recall there is something that does it when you start up after changing the
number of files to keep, but I don't recall if that is tested over some
loop regularly.

Is there some way to make it auto-detect when it should be enabled? If not,
please document that it should be used on ZFS and any other file system
with CoW properties on files.