I need write a query like this select coalesce_agg(col order by col asc) from some_table group by other_col
clearly the col column is nullable. which is the best way (in terms of performance too) to obtain this? Are there any built-in aggregate function or should I write a new aggregate function with CREATE AGGREGATE? Do you think coalesce_agg should be a built-in aggregation? Thanks in advance -- Federico Dal Maso
