On 13.02.2013 15:31, Alexander Korotkov wrote:
> On Wed, Feb 13, 2013 at 4:51 PM, Greg Stark<stark@mit.edu> wrote:
>
>> Heikki was talking about a generic WAL record type that would just
>> store a binary delta between the version of the block when it was
>> locked and when it was unlocked. That would handle any extension
>> cleanly as far as data modification goes as long as the extension was
>> working through our buffer manager. It seems like an attractive idea
>> to me.
>
> It will, for sure, works well when atomic page changes are enough for us.
> However, some operations, for example, page splits, contain changes in
> multiple pages. Replaying changes in only some of pages is not fair. Now,
> it's hard for me to imagine how to generalize it into generic WAL record
> type.
You could have a generic WAL record that applies changes to multiple
pages atomically.
- Heikki
