Hi, I am interested in calculating running sums, and therefor I looked for something like 'SUM OVER'. Since that doesn't exist, I looked into 'RANK OVER', and am trying to implement 'SUM OVER' according to that. I am looking at sql_rank_grp() in sql.c and rel_rankop() in rel_select.c, and am thinking how to modify them to support running sum. However, I can't figure out how to add another column to the parameters that sql_rank_grp gets (the column I want to sum over). I can't figure out how these two functions work together. Where are the incoming parameters for sql_rank_grp() created? I can see that rel_rankop() fills an sql_exp struct with the 'group by' and 'order by' columns, but I cannot find where to go from there. Any kind of guidance in the right direction would be appreciated. Thanks. -- View this message in context: http://www.nabble.com/rank-over%2C-sum-over-tp23543557p23543557.html Sent from the monetdb-users mailing list archive at Nabble.com.