On 3/6/19 10:38 AM, Robert Haas wrote:
> On Wed, Feb 27, 2019 at 6:12 PM Alvaro Herrera <alvherre@2ndquadrant.com> wrote:
>> I think the idea of it being a generic tunable for assorted behavior
>> changes, rather than specific to WAL recycling, is a good one. I'm
>> unsure about your proposed name -- maybe "wal_cow_filesystem" is better?
> I *really* dislike this. For one thing, it means that users don't
> have control over the behaviors individually. For another, the
> documentation is now quite imprecise about what the option actually
> does, while expecting users to figure out whether those behaviors are
> acceptable or preferable in their environment. It lists recycling of
> WAL files and zero-filling of those files as examples of behavior
> changes, but it does not say that those are the only changes, or even
> that they are made in all cases.
>
So you want two options, like wal_recycle_files and wal_zero_fill, both
defaulting to true? Is there a reasonably use case for turning one off
without the other?
Alternatively, we could remove the 'for example" wording, which I agree
is unfortunate.
cheers
andrew
--
Andrew Dunstan https://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
