What are some alternatives?
When comparing PostgreSQL and MySQL, you can also consider the following products
SQLite - SQLite Home Page
Oracle DBaaS - See how Oracle Database 12c enables businesses to plug into the cloud and power the real-time enterprise.
Oracle Database 12c - Simplify database management and automate the information lifecycle with maximum security.
MongoDB - MongoDB (from "humongous") is a scalable, high-performance, open source NoSQL database.
Microsoft SQL Server - Microsoft Azure is an open, flexible, enterprise-grade cloud computing platform. Move faster, do more, and save money with IaaS + PaaS. Try for FREE.
DB2 - IBM Db2 is database software that can reliably handle multiple workloads and the latest version of Db2 is optimized to provide extreme performance while lowering costs.