Re: patch to allow disable of WAL recycling

Hi,

On 2018-07-10 14:15:30 -0600, Jerry Jelinek wrote:
>  Thanks to everyone who took the time to look at the patch and send me
> feedback.  I'm happy to work on improving the documentation of this new
> tunable to clarify when it should be used and the implications. I'm trying
> to understand more specifically what else needs to be done next. To
> summarize, I think the following general concerns were brought up.
> 
> 1) Disabling WAL recycling could have a negative performance impact on a
> COW filesystem if all WAL files could be kept in the filesystem cache.

> For #1, #2 and #3, I don't understand these concerns. It would be helpful
> if these could be more specific

We perform more writes (new files are zeroed, which needs to be
fsynced), and increase metadata traffic (creation of files), when not
recycling.

Regards,

Andres