Dear all, I am trying to create aggregate functions and I see there are more than one function descriptors for one single function. For example the function array_count(collection) has the following descriptors:
- ScalarCountAggregateDescriptor - SerializableCountAggregateDescriptor - CountAggregateDescriptor I am not sure I understand the difference between each of this. Can you please provide and example or point me to a documentation entry to learn how to properly implement aggregate functions? The function I am trying to implement is ST_Extent. <https://postgis.net/docs/manual-1.4/ST_Extent.html> Thank you. Yours sincerely, Riyafa
