PostgreSQL provides enterprise-level services that guarantee the continuation of the business. For example, PostgreSQL supports replication, which enables the developers to provide HA solutions. PostgreSQL can integrate data from different data sources; this makes it easy for developers to use it for ETL jobs. In addition, PostgreSQL security is treated as a first-class citizen. Security update patches are shipped in minor releases to make it easier for administrators to upgrade PostgreSQL.
Finally, the features of PostgreSQL are endless: PostgreSQL provides advanced SQL statements, very rich extensions, and interactive tools.