"Too far out of the mainstream"

Hello all,

I would like the community's input on a topic. The words "too far out of the mainstream" are from an e-mail we received from one of our clients, describing the concern our client's IT group has about our use of PostgreSQL in our shop. The group in question supports multiple different databases, including Oracle, MySQL, SQLServer, DB2, and even some non-relational databases (think Cobol and file-based storage), each type with a variety of applications and support needs. We are in the running for getting a large contract from them and need to address their question: "What makes PostgreSQL no more risky than any other database?"

Thanks in advance for your input.

Andy Yoder