These kinds of roll ups are very common. They have simple mathematical
properties. There is a simplifying abstraction to be found here. Please find it
and use it.
Julian
> On Feb 2, 2022, at 7:47 PM, Thomas D'Silva wrote:
>
> Hi Stamatis,
>
> Thanks for your response. Your suggestion of
Hi Stamatis,
Thanks for your response. Your suggestion of having use case specific rules
that translate time ranges that align on the rollup of the materialized
view makes sense.
However if the time range doesn't align for eg. if we have a view that
rolls up to the minute and the query predicate
Hi Thomas,
I haven't looked into the implementation details of the rule but I assume
the rewriting does not kick in because there is no easy way to relate the
"ts" column that is used in the query with the "floor(ts to minute)" column
that is materialized.
I assume that if your query is/was
Xurenhe,
Thank you for the detailed response and pointers. The use case you
describe for OLAP streaming queries is similar to what our team is trying
to accomplish.
We use calcite to query data stored in kudu [1]. We use kafka streams to
maintain materialized views that contain pre-aggregated
It’s useful in OLAP.
Time ’s prediction bottom `Aggregate` could be pulled-up, because of Time’s
granularity in Aggregate’s group.
By the way, the query can be rewritten by mv, when the query's granularity
is coarser than mv’s.
eg:
-- mv:
SELECT eventid, floor(ts TO minute), count(*) as cnt
Stamatis,
For the materialized view and query that I had mentioned in the earlier
email, I got the following final plan that used the table :
EnumerableCalc(expr#0..2=[{inputs}], EXPR$0=[$t1], EXPR$1=[$t2])
EnumerableAggregate(group=[{0, 1}], EXPR$1=[COUNT()])
Hey Thomas,
Can you post the plan/query that you were expecting after the rewriting?
Is the behavior you observed specific to timestamps?
Best,
Stamatis
On Thu, Jan 27, 2022 at 4:07 AM Thomas D'Silva
wrote:
> Justin,
>
> Thanks for your response. If I change the query predicate to "floor(ts
Justin,
Thanks for your response. If I change the query predicate to "floor(ts to
minute) >= timestamp'2018-01-01 00:01:00' AND floor(ts to minute) <
timestamp'2018-01-01 00:05:00'" it does end up querying the view.
However I want to be able to query an arbitrary time range and have the
union
Hi,
The existing MaterializedViewRule is not applied when the materialized view
does not have a view predicate but the query contains a predicate. For eg
for the following materialized view
SELECT eventid, floor(ts to minute), count(*) as cnt
FROM events
GROUP BY eventid, floor(ts TO
