[ozgune]

Reading through your comment again, I realize I completely missed the mark on your question.

If you use Citus, you don't have to make any changes in your application. You just need to remodel your data and define your tables' sharding column(s). Citus will take care of the rest. [1]

In other words, your app thinks it's talking to Postgres. Behind the covers, Citus shards the tables, routes and parallelizes queries. Citus also provides transactions, joins, and foreign keys in a distributed environment.

[1] Almost. Over the past two years, we've been adding features to make app integration seamless. With our upcoming release, we'll get there: https://github.com/citusdata/citus/issues/595