this takes 1 second (or less) on duckdB:
select sum(sin(x)) from range(1 ,300001)cnt(x)

so 10 seconds are due to not liking "recursive" CTE in a 300 000 loop (30 000 loop /second limit)

Then there is a big slowdown in using UDF, versus SQLite.
( 3 000 loop/second limit, versus 300 000 loop/second for SQLite)

not using "recursive" CTE and not using UDF (in this test) makes it quick like SQLite

when duckdb gets less bad at UDF, it will be an interesting change
becoming fluent with massive datas makes tcl/tk a problem.

This takes 10 seconds to duckdb

pydef py_sin(s:int) ->float:
    "sinus function : example loading module, handling input/output as strings"
    import math as py_math
    return ( py_math.sin(s*1));

WITH  
  cnt(x) AS (
     SELECT * from generate_series (1, 30000 )
  )

select sum(py_sin(x))  from cnt 
`````


This takes 0.1 second to duckdb
`````
WITH cnt(x)  AS (select * from generate_series(1, 3000000)  )

select sum(sin(x))  from cnt ;
````