Hi Orest,
We were initially running our system with a local application server which uses JDBC against a cloud Hana server and with a 100+ ms ping there was a significant performace impact. At 150ms your update is probably doing at least a single round trip of 300ms. You can run the update locally on the database and see how quickly it returns vs. running it remotely and this will give you a rough idea of the impact that network latency is having on your performance.
Thanks,
Jason