Data mining + bitcoind

I am new to data mining and understand that the best starting point would be a database. I'd like to reduce the amount of pre-processing as much as possible so if viable i'd like a solution the updates everytime a new block comes in.

From a few google searches i've been led to believe that a relational database best suits my needs.

The information i require would be tied to a PubKey, essentially it's history , when it was first used, how many times it has appeared , in what capacity (source/destination), what amounts it has been used with (in/out), what Pubkeys it has sent to /received from and what other Pubkeys have provided source funds in transactions with it.

Has anyone doe anything of the sort? Did you modify the source code or use an external app ? What was the size of the resulting database ? How portable was your solution and is it scalable ?

Thanks