Re: Pluggable Indexes (was Re: rmgr hooks (v2))

On Thu, Jan 22, 2009 at 11:13 AM, Heikki Linnakangas
<heikki.linnakangas@enterprisedb.com> wrote:
> Simon Riggs wrote:
>> On Thu, 2009-01-22 at 16:15 +0200, Heikki Linnakangas wrote:
>>>
>>> That might be useful. But again, could just as well be implemented as an
>>> external tool like pglesslog.
>>
>> There is no WAL record for "no-op", at least not one of variable length.
>
> Hmm, maybe there should be? That seems like a useful thing to have for
> external tools.
>
>> The WAL files can't just have chunks of zeroes in the middle of them,
>> they must be CRC valid and chained together in the exact byte position.
>> There isn't any way to do this, even if there were, that's a seriously
>> complex way of doing that.
>
> Hmm, I think you could remove the records in the middle, rechain the
> remaining ones, recalculate the crc, and put an xlog switch record at the
> end. I agree that's seriously complicated, a no-op record would be much
> simpler.

Would I be pushing my luck if I suggested that maybe a pluggable rmgr
would also be much simpler, and we already have a patch for that?  :-)

...Robert