Re: GSoC Query

Similarly using the no. of select hits on a table we can check that if maximum no. of times it is on a non-index field we can index on that field to make select faster.

It's impractical to figure out where indexes should go at without simulating what the optimizer would then do with them against a sample set of queries.  You can't do anything useful just with basic statistics about the tables.

I would recommend http://msdn.microsoft.com/en-us/library/aa226167(SQL.70).aspx as a good, practical introduction to the topic of what it takes to figure out where indexes go at, from someone who came up with a reasonable solution to that problem.  You can find a list of the underlying research they cite (and an idea what has been done since then) at http://portal.acm.org/citation.cfm?id=673646