Re: counting algorithm for incremental matview maintenance

On Wednesday, May 15, 2013 1:22 AM Kevin Grittner wrote:

Good explanation for understanding the initial concept of incremental update
of matviews.

> The original and modified versions of the relations (tables or
> other matviews) which define a matview must be available to
> calculate the matview deltas, so the snapshot information for this
> must be available and registered until the matview delta has been
> calculated.  They can be released once the delta has been
> established and before it has been applied to the matview. 

Here by modified versions of the relations, do you mean to say delta
relations for recording changes.
Could you elaborate a bit about snapshot information, is this snapshot is
for delta relation, when will it acquire snapshot information to
Update matviews?

> Initial
> milestones in this development will focus on "eager" maintenance,
> so this will not initially be a big issue, but will become more
> important as we work on making more of the work asynchronous, so
> that the foreground query is not held up maintaining data which is
> allowed to be a little stale. This seems not entirely unrelated to
> background worker processes and snapshot sharing.

With Regards,
Amit Kapila.