Returns an array consisting of all values in
expr within the group.
expr: An expression of any type.
cond: An optional boolean expression filtering the rows used for aggregation.
An ARRAY of the argument type.
The order of elements in the array is non-deterministic.
NULL values are excluded.
DISTINCT is specified the function collects only unique values and is a synonym for collect_set aggregate function
This function is a synonym for array_agg