In 2025, the database ecosystem has evolved into a highly interconnected and diverse landscape, characterized by openness, intelligence, and composability. Modern databases integrate seamlessly with each other, leveraging open formats like Parquet and Iceberg to enhance interoperability and reduce vendor lock-in risks. AI advancements have enabled non-technical users to perform data queries and analyses, while also optimizing performance through automated recommendations for indexing and query optimization. The choice of database involves understanding the trade-offs between different data structures, such as B-trees and LSM-trees, which cater to different performance needs, whether for read or write-heavy workloads. Additionally, the decision-making process involves evaluating data organization methods, compression techniques, and transactional requirements to align with specific business needs. Ultimately, the successful deployment of databases in 2025 depends on creating a composable data architecture that utilizes the right tools for transactional, analytical, and vector processing, rather than relying on a single, one-size-fits-all solution.