Its difficult to give answer without understanding of data processing you want.<p>If you need to generate rich multi-dimension reports I recommend you create  ETL pipeline into star-like sharded database (ala OLAP).<p>Dimensions normalization sometime dramatically reduce data volume, most of dimensions even can fit into RAM.<p>Actually 200Gb per day not so much in terms of throughput, you can manage it pretty well on PostgreSQL cluster (with help of pg_proxy). I think mySQL will also work OK.<p>Dedicated hardware will be cheaper then AWS RDS.