1. A system comprising: a memory to store a set of data in a data structure having a plurality of rows and a plurality of columns, and metadata for the set of data; a rules engine to determine one or more operations on particular columns of the set of data according to a set of rules, wherein a rule of the set of rules includes conditions defined in terms of the metadata, wherein the rule includes comparing a metadata attribute of a first column with a metadata attribute of a second column, and wherein the rules engine determines a count for one or more rules in the set of rules, each count having an associated rule in the one or more rules, and wherein each count is based on a number of times the rules engine has generated a column using the associated rule; a data analysis tool to perform the determined operations and to rank the one or more rules based on their associated counts; and a display device to present results of the determined operations as an additional column to the plurality of columns and to display the one or more rules to a user in an order consistent with their ranking.
5. The system of claim 1 , wherein the rule further includes determining that the first column includes data of a first type for a first time period and the second column includes data of the first type for a second time period, and the rule defines a formula for a growth column.