aggregation group by column popup

'Group by' column

A 'group by' column is needed when performing an aggregation.

This can be:

during an aggregation within a table, or
during a join, when the values that you wish to joined need to be aggregated; the selected key 2 column will act as a 'group by' column.

When a 'group by' column is used:

groups are formed for all records in the table that have the same class name, or ID in the specified 'group by' column,
then, the specified aggregation function calculates the sum, average, etc. of values per group.