Retrieve results in PostgreSQL stored procedure allowing query parallelism

I want to execute an SQL query and process its results inside a stored
procedure without preventing query parallelism. Since I don't want to
prevent query parallelism, cursors can't be used, and I would like to
avoid creating a temporal table.

Is this possible? If so, what is the best way to execute the query,
retrieve all results in memory, and process them inside the stored
procedure?

-- 
Joan Pujol