Re: WAL consistency check facility

On Thu, Sep 1, 2016 at 11:32 AM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> On Wed, Aug 31, 2016 at 7:02 PM, Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:
>> On 27 August 2016 at 12:09, Kuntal Ghosh <kuntalghosh(dot)2007(at)gmail(dot)com> wrote:
>>
>>>>> * wal_consistency_mask = 511 /* Enable consistency check mask bit*/
>>>>
>>>> What does this mean? (No docs)
>>>
>>> I was using this parameter as a masking integer to indicate the
>>> operations(rmgr list) for which we need this feature to be enabled.
>>> Since, this could be confusing, I've changed it accordingly so that it
>>> accepts a list of rmgrIDs. (suggested by Michael, Amit and Robert)
>>
>> Why would we want that?
>
> It would be easier to test and develop the various modules separately.
> As an example, if we develop a new AM which needs WAL facility or
> adding WAL capability to an existing system (say Hash Index), we can
> just test that module, rather than whole system. I think it can help
> us in narrowing down the problem, if we have facility to enable it at
> RMGR ID level. Having said that, I think this must have the facility
> to enable it for all the RMGR ID's (say ALL) and probably that should
> be default.

As far as I am understanding things, we are aiming at something that
could be used on production systems. And, honestly, any people
enabling it would just do it for all RMGRs because that's a
no-brainer. If we are designing something for testing purposes
instead, something is wrong with this patch then.

Doing filtering at RMGR level for testing and development purposes
will be done by somebody who has the skills to filter out which
records he should look at. Or he'll bump into an existing bump. So I'd
rather keep this thing simple.
--
Michael