Big data vs traditional BI: when is “big” actually necessary?

Traditional BI suits scenarios where data sources are stable and structured, and queries or reports run on manageable volumes using definable relational sets. “Big data” becomes necessary as data volumes explode, sources multiply, formats change rapidly, or real-time analytics is crucial. Choose classic BI for mature companies or highly regulated environments, and use big data techs for innovation, IoT, or complex, growing data.