Cassandra aggregate function "first_row"

Question

I know, that Cassandra allows to GROUP BY and can run UDF on that data.

Is there any default function to get the first row of each aggregated set?

(How) Can I stop processing data and return result from my UDF immediately (E.G. After 1 or few rows processed)?

Now I'm using ... COUNT(1) ... as workaround.

Answer 1

Actualy You fon't need any UDF. It works as described out of the box.

Jusr GROUP BY fields you need.