The text discusses the complexities and considerations involved in selecting a database or database as a service (DBaaS) for modern applications, highlighting the differences between traditional relational databases and the diverse array of NoSQL databases designed to handle web-scale operational applications. It outlines the distinct characteristics and workloads of OLTP (online transaction processing) and OLAP (online analytical processing), emphasizing the need for application architects to understand and evaluate workloads to achieve optimal performance. The text also underscores the growing trend of mixed workloads and the necessity to integrate various database solutions to meet business requirements, while acknowledging the challenges posed by a wide variety of databases with different data models, query languages, and performance characteristics. It concludes by noting that, despite the availability of new database technologies, the fundamental business and application requirements remain unchanged, emphasizing the importance of understanding and translating workload requirements into effective database operations.