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
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Federico Dal Maso