GreptimeDB is the open-source Observability 2.0 database — treating metrics, logs, and traces as unified wide events instead of three separate pillars. The three-pillar model (Prometheus + Loki + Jaeger) creates data silos, redundant infrastructure, and cross-signal correlation pain. GreptimeDB replaces all three with one columnar engine on object storage: cross-signal SQL JOINs, up to 50x cost reduction, and native support for AI agent observability via OpenTelemetry GenAI conventions. Key advantages: full-text log indexing (vs. Loki's label-only), SQL + PromQL without a separate data warehouse, 45x less trace storage vs. Elasticsearch, and Jaeger-compatible migration in one week. Written in Rust, OpenTelemetry-native, Kubernetes-ready. Used in production processing billions of data points daily — including OB Cloud across 170+ availability zones. Open-source (Apache 2.0) · Enterprise · GreptimeCloud (fully managed)