correct return type needed for returning additional attributes in case of window function about plr HOT 3 CLOSED

As the error says, window functions cannot return a set. You want to return a record, not a table! Change return type like this

CREATE OR REPLACE FUNCTION TS_DER_01_31(numeric, out TS_DER_01_31_size numeric, out TS_DER_01_31_time_index numeric)
AS
$BODY$
...

But it is somewhat useless IIRC. I'm not sure if there is an easy way to unpack that record from a window function. I am not sure whether registered composite type can help to return several values from a window function. Also it is somewhat inefficient to use ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW as lots of stuff being passed to R again and again, you'd be better off doing that in R while using the whole window frame as it is special cased. With all that, perhaps, it is easier to write a regular function returning a set of / table, not a window one.

from plr.

create type myout as (a float8, b float8);

CREATE OR REPLACE FUNCTION TS_DER_01_31(numeric)
RETURNS myout AS
$BODY$
as.list( base::tryCatch(expr=as.numeric(feasts::shift_level_max(farg1)), error=function(e){c(NA,NA)}) )
$BODY$
LANGUAGE 'plr' WINDOW;

-- test function:
select *, (TS_DER_01_31).*
from (
  select *,
  TS_DER_01_31(usage) OVER w
  from ts_der_sample where custid < 3
  WINDOW w AS (PARTITION BY custid ORDER BY month ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW)
) foo;

from plr.

no response from OP

from plr.