Partitioning By Counts In Sql

This issue is related to question I asked here. I have a table that looks like this: Item Count 1 1 2 4 3 8 4 2 5 6 6 3 I need to group item

Solution 1:

Why isn't this a correct result?

Item    Group   Count  
111224338442556613

Or this?

Item    Group   Count  
111224338442556663

Seems to me that you're trying to solve the answer 'how to group the items as to minimize the number of groups and maximize the number of items in each group, w/o exceeding the limit 5'. Which sounds a lot like the Knapsack problem. Perhaps a you should read the Celko's SQL Stumper: The Class Scheduling Problem and the solutions proposed. Others have also approached this problem, eg. And now for a completely inappropriate use of SQL Server. Heads up: this is no a trivial problem by any means. Any naive algorithm will die a slow death attempting to solve it on a 1M rows table...