So more from here: https://eng.uber.com/schemaless-part-two/ https://eng.uber.com/schemaless-part-two/ "Each Schemaless shard is a separate MySQL database, and

So more from here: https://eng.uber.com/schemaless-part-two/ https://eng.uber.com/schemaless-part-two/ "Each Schemaless shard is a separate MySQL database, and each MySQL database server contains a set of MySQL databases. Each database contains a MySQL table for the cells (called the entity table) and a MySQL table for each secondary index, along with a set of auxiliary tables." So... 1 table, with 1 index and manually created and updated secondary index tables. With this scheme I can only assume postgres will work just as well or better.