This article discusses the differences between a relational database optimized for online transactions and a data warehouse optimized for processing and summarizing large amounts of data. It also explores how databases and data warehouses can be used to support decision making and trend analysis in large organizational environments. The article provides examples of how Twitter, managers, and organizations utilize databases to support decision making. Additionally, it provides examples of how data warehouses and data mining can be used to support trend analysis and decision making in large organizational environments.