How-to: Computations

How to read these sections

1. GROUP SUM: Summing up values through grouping.
2. GROUP MAX/MIN/AGGR: Searching for maximum/minimum values through grouping.
3. CASE/IF/OVERRIDE: Branching and selection from a set of values.
4. GROUP LAST: Searching for the last value through grouping.
5. GROUP CONCAT: Merging lines through grouping.
6. PARTITION: Distributing values across multiple lines.