Re: Materialized views WIP patch

Robert Haas wrote:
> Josh Berkus wrote:

>> Being empty (in an inaccurate way) is just one kind of stale data.
> 
> This is my feeling also.

If you had an MV summarizing Wisconsin courts cumulative case counts
by case type, "empty" would not have been a valid "stale" state for
over 150 years. That is a degree of staleness that IMV is not just a
quantitative degree of staleness, as if a nightly recalculation had
failed to occur, but a qualitatively different state entirely. While
you may or may not want to use the stale data if last night's regen
failed, and so it should be under application control, I can't
imagine a situation where you would want to proceed if the MV didn't
have data that had at some time been correct -- preferrably at some
time since the invention of digital electronic computers. Could you
provide an example where it would be a good thing to do so?

-Kevin