Teradata. It's a monster. I can query a 30 billion row table and get a summary in 10 seconds or less. SQL server with a monster 3 TB of RAM takes 30 seconds for same using a columnstore index, CS indexes and FTI indexes are great in SQL... 30s still lightning fast relatively speaking. Greenplum/postgres would take 30 minutes for that type of aggregate query. Postgres free, so benefit there.