Thank you for your answer and your hint regarding the user-mailing list.
I already got an answer via datastax forum
(https://community.datastax.com/questions/3804/using-a-user-defined-type-in-user-defined-aggregat.html).
On 2020/05/04 08:49:16, Benjamin Lerer wrote:
> Hi Andrea,>
>
> Question 1) When I call the aggregate, I would like to pass sample_size>
> > with a sub-query, e.g.>
> > ==> "SELECT bloomfilter_uda(name, (SELECT count(*) FROM test_table))>
> > FROM test_table;" <==>
> >>
> Is that possible with Cassandra?>
>
>
> Sub queries are not supported by Cassandra.>
>
> Question 2) When I try to register the bloomfilter_uda, I get the>
> > following error:>
> > ==> InvalidRequest: Error from server: code=2200 [Invalid query]>
> > message="Invalid set literal for (dummy) of type bloomfilter_udt" <==>
> > Can I just pass Cassandra data types as a state (map, list, set)?>
>
>
> Sorry, this question is not clear to me. Do you have a specific
example?>
>
> Question 3) If I assume, all of the above is my bad, how can I access>
> > the props of the state? Like>
> > ==> state.n_as_sample_size <==>
> > Is this somehow possible?>
> >>
>
> You cannot access the state. You can only access the value returned
by the>
> aggregate so something like SELECT bloomfilter_uda(name, count) [...]>
> Once you get the UDT value you can get the information you want from it>
> based on which driver you are using (e.g. java:>
> https://docs.datastax.com/en/developer/java-driver/3.7/manual/udts/).>
> If you are only interested in one field you can directly get the field>
> value using SELECT bloomfilter_uda(name, count). bloom_filter_as_map>
> [...]>
>
> Those questions are more suited for the user mailing list. The dev
mailing>
> list is for discussion on C* internal developments.>
>
>
>
> On Sat, May 2, 2020 at 12:01 PM Andreas R. >
> wrote:>
>
> > Hello everybody,>
> >>
> > I am new to Cassandra and I am trying to extract sketches (e.g. bloom>
> > filter) database side from some given data. I came across user
defined>
> > types/functions/aggregates and coded some simple implementation.
But now>
> > I am stuck, my questions break down to the below:>
> >>
> > 1. CREATE TYPE bloomfilter_udt (>
> > 2. n_as_sample_size int,>
> > 3. m_as_number_of_buckets int,>
> > 4. p_as_next_prime_above_m bigint,>
> > 5. hash_for_string_coefficient_a list ,>
> > 6. hash_for_number_coefficients_a list ,>
> > 7. hash_for_number_coefficients_b list ,>
> > 8. bloom_filter_as_map map>
> > 9. );>
> > 10.>
> > 11. CREATE OR REPLACE FUNCTION bloomfilter_udf (>
> > 12. state bloomfilter_udt,>
> > 13. valuetext,>
> > 14. sample_size int>
> > 15. )>
> > 16. CALLED ON NULL INPUT>
> > 17. RETURNS bloomfilter_udt>
> > 18. LANGUAGE java AS>
> > 19. $$>
> > 20. //fill state which is user defined type bloomfilter_udt with
some data>
> > 21. returnstate;>
> > 22. $$>
> > 23. ;>
> > 24.>
> > 25. CREATE OR REPLACE AGGREGATE bloomfilter_uda (>
> > 26. text,>
> > 27. int>
> > 28. )>
> > 29. SFUNC bloomfilter_udf>
> > 30. STYPE bloomfilter_udt>
> > 31. INITCOND {}>
> >>
> > Question 1) When I call the aggregate, I would like to pass
sample_size>
> > with a sub-query, e.g.>
> > ==> "SELECT bloomfilter_uda(name, (SELECT count(*) FROM test_table))>
> > FROM test_table;" <==>
> > Is that possible with Cassandra?>
> >>
> > Question 2) When I try to register the bloomfilter_uda, I get the>
> > following error:>
> > ==> InvalidRequest: Error from server: code=2200 [Invalid query]>
> > message="Invalid set literal for (dummy) of type bloomfilter_udt" <==>
> > Can I just pass Cassandra data types as a state (map, list, set)?>
> >>
> > Question 3) If I assume, all of the above is my bad, how can I access>
> > the props of the state? Like>
> > ==> state.n_as_sample_size <==>
> > Is this somehow possible?>
> >>
> > I'd appreciate some help/hints.>
> > Thanks>
> > Andreas>
> >>
>
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