Abstract: While open-source databases have become a cornerstone of the industry, challenges related to operational costs, enterprise-grade support, and trust in locally developed solutions remain prominent. Taking OceanBase as an example, this article systematically examines its architectural evolution and core innovations, tracing its development from a layered read-write separation design, to a fully peer-to-peer distributed architecture, and finally to an integrated standalone-friendly, scale-on-demand model. The article distills three key insights for distributed database engineering: vertical and horizontal scaling must be balanced; architectural design should prioritize stable, operable solutions over the blind pursuit of theoretical optimality; and next-generation databases must deeply adapt to the demands of multi-model data management and hybrid retrieval in the AI era. OceanBase’s experience offers a pragmatic path for domestic open-source databases that reconciles technical depth with real-world industrial adoption.