There are times when I want to filter Database (Collection) entries and then “reduce” that with my own custom logic. Basic operations such as “Sum”, “Min”, “Count” seems to be supported but there could be tons of custom reducer logic.
An example is say I have a string column in my Collections and after filtering to a subset of rows I would like to concatenate this column values with comma separator in between. Answer to this particular scenario would be helpful. Also, I would like to know what is the design pattern when you need your custom reducer logic.