Inconsistency in Querying Riak TS?

John Daily jdaily at basho.com
Mon Oct 17 22:00:24 EDT 2016


One of the catches regarding the quantum limit is that unless the
query starts exactly on a boundary, the effective limit is one fewer
because it is determined by the number of partitions the query has to
touch.

I suspect that's the behavior you're seeing.

Sent from my iPhone

> On Oct 17, 2016, at 9:38 PM, Joe Olson <technology at nododos.com> wrote:
>
> According to the documentation at
>
> https://docs.basho.com/riak/ts/1.4.0/using/querying/guidelines/
>
> "A query covering more than a certain number of quanta (5 by default) will generate the error too_many_subqueries and the query system will refuse to run it. Assuming a default quantum of 15 minutes, the maximum query time range is 75 minutes."
>
> However, the example shows a table of quantum 15 seconds. After the example:
>
> "The maximum time range we can query is 60s, anything beyond will fail."
>
> ....which seems to contradict the first assertion.
>
> Furthermore, I have been getting inconsistant behavior using the quantum.
>
> I have a code snippet placed here, demonstrating this behavior:
>
> https://gist.github.com/anonymous/a4a4ccb8617a00d38fb47a6b11571d81
>
> In this example, I set up two tables, one with a quantum of 6 hours, another with a quantum of 12 days.
>
> I am using the default range (5) on my cluster.
>
> A query spanning 5 quantum partitions is allowed on the 6 hour table, a query spanning 5 quantum partitions
> on the 12 day table fails with the 'too many subqueries' error.
>
> Are the number of allowed subqueries different depending on the quantum size?
>
> If so, is there more detailed documentation on the subject?
>
> Thanks!
>
>
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