Re: WAL consistency check facility

On Wed, Aug 31, 2016 at 8:26 PM, Amit Kapila <amit.kapila16@gmail.com> wrote:
>> As far as I am understanding things, we are aiming at something that
>> could be used on production systems.
>>
>
> I don't think you can enable it by default in production systems.
> Enabling it will lead to significant performance drop as it writes the
> whole page after each record for most type of RMGR ID's.
>
>> And, honestly, any people
>> enabling it would just do it for all RMGRs because that's a
>> no-brainer.
>
> Agreed, but remember enabling it for all is not free.

I have sympathy for the idea that this should be as low overhead as
possible, even if that means adding complexity to the interface --
within reason. I would like to hear a practical example of where this
RMGR id interface could be put to good use, when starting with little
initial information about a problem. And, ideally, we'd also have some
indication of how big a difference that would make, it terms of
measurable performance impact.

-- 
Peter Geoghegan