Is vertica a data warehouse?

Vertica itself is not a data warehouse (dwh). It is a platform that might be the foundation for dwh. And there are quite a lot real dwh deployments based on Vertica. Especially with some hybrid data models based of Data Vault and Anchor Modeling approaches, that are optimized for MPP storage and processing. The dwh is not something that you buy and deploy. Any dwh assumes that you are not only establishing some fantastic technologies to handle data processing - it is also about data management processes and strategy. Thus, most probably together with the analytics platform like Vertica you might need other stuff: data quality tools, data governance, policy management and etc. Of course it will require special competencies to handle it.