Category theory and query optimization
I am considering this for my thesis, but I can't find any work about applying category theory to query optimization, and this frightens me a bit: looks like someone has long ago proved that this is impossible (why would it be?), and now noone even tries.
Could you give me pointers to some works on the topic? I've googled the hell out of the internet, I found some works on formalizing data models with CT but nothing on exactly optimization.