Up until just a week ago or so, @arcange ran SteemSQL database as a free SQL database mirror of the blockchain. Since then he has switched to a paid subscription model with the steep fee of 10 SBD monthly. It is easy for me to justify this fee so I am paying it, but understood it is quite steep when taken out of context. For me, I do all my curating for @curie using custom search queries I have created. I earn 10 STEEM per approved submission to @curie as a finder's fee and see ~9-10 posts approved per week = no brainer for me to pony up for the DB access :)