Re: materialized view scannability in other DBs

Robert Haas <robertmhaas@gmail.com> wrote:
> Kevin Grittner <kgrittn@ymail.com> wrote:

>> It seems to me pretty fundamental to have a way to avoid quietly
>> generating completely bogus results

> I understand that it seems fundamental to you.  What I'm trying
> to establish is that reasonable people could disagree about that.
> I think the fact that Oracle doesn't have one is a compelling
> argument for that position.

Oracle has a "staleness" property for matviews which is set to
UNUSABLE when the matview is not populated.  The fact that this
only prohibits use of the matview for query rewrite and not direct
reference is more a reflection of the orientation of Oracle toward
using matviews to accelerate queries written against the base
tables, much as indexes do.  Direct access seems to be taken as
more useful for diagnostic purposes.  Still, if you want to have
application-side responsibility for not using matviews when they
are not populated, the application can check this "staleness"
property.  You don't seem to be suggesting that we provide any
equivalent.

--
Kevin Grittner
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