Thank you for your reply. I actually found your blog post regarding this topic and browsed through it, but it did not yield the answer I was looking for. In fact, it seems impossible to do what I wish to do without defining a UDA for this specific use case -- something that is not practical to do when all of my queries use 'group by'.
For example, I ave a query like this: select sum(a), avg(a), min(a), max(a), MY_UDF(my_set_column) from my_table group by a; I would hope that using a UDF for my_set_column would allow me to combine all of the my_set_columns passed in via group by, but I cannot pass state to the UDF. A UDA can accept state, but that would require me rewriting the whole query to be: select MY_UDA(a, my_set_column) from my_table; Additionally, I would need a separate UDA for each of the different group by clauses. Is there no way around this? I would really like to be able to simply add a data column of type set<bigint> and then get all of the unique members in this set across an aggregation. On Tue, Oct 23, 2018 at 1:44 PM DuyHai Doan <doanduy...@gmail.com> wrote: > You will need to use user defined aggregates for this > > Le 23 oct. 2018 16:46, "Joseph Wonesh" <joseph.won...@sticknfind.com> a > écrit : > >> Hello all, >> >> I am trying to aggregate rows which each contain a column of >> Set<BIGINT>. I would like the result to contain the sum of all sets, where >> null would be equivalent to the empty set. I expected a query like: "select >> sum(my_set_column) from my_table group by my_key_column" to do this, but >> the set type is not supported by this aggregate. Does anyone know of a way >> to aggregate this using existing cassandra built-ins? Thanks! >> >> This message is private and confidential. If you have received message in >> error, please notify us and remove from your system. > > -- This message is private and confidential. If you have received message in error, please notify us and remove from your system.
