I'm looking for an example application to motivate some research. Here's the idea: our algorithm allows one to efficiently traverse an index, sorted by multiple fields, with arbitrary ascending or descending specifications on each field.
So if you have an index on your email like: subject asc, from asc, date asc. Then we can efficiently traverse, for example: subject desc, from asc, date desc.
Anyone know of any applications (end user or domain specific) that let you sort data by multiple fields?
I was thinking of any sort of app that lets you view data in a table, and clicking on a table header sorts the data by that column. A second click on the same header reverses the sort. What I need now is an example of an application that lets you "pin" a sort on one column, then choose a secondary sort on another column (like sort by "from", then a secondary sort on "subject").
