DolphinDB vs GreptimeDB

DolphinDB is a real-time analytics and stream-processing platform built around a high-performance time-series database. Its storage engines cover time-series databases, OLAP and in-memory OLTP workloads, with more than 1,500 built-in analytical functions and more than 10 streaming engines. Batch and stream processing can use the same metric expression. Programming options include imperative, vectorized, functional and SQL paradigms. The distributed system supports horizontal scaling, load balancing, fault tolerance, distributed transactions and high availability across data nodes, controllers, streaming and API clients. Deployment options include cloud, on-premise and hybrid environments. Listed use cases span finance, energy, power, transportation, industrial manufacturing and scientific research. The Community Edition has a free perpetual license, limited to two nodes, each with two CPU cores and 8 GB RAM. A free Enterprise Trial supports high-availability clusters and includes expert technical support. Related components include Swordfish for embedded use, Shark for GPU workloads, Starfish for quantitative research workflows and Octopus for complex event processing. The product is available through API, extension, Linux, self-hosted, web and Windows options.

GreptimeDB is an open-source observability database for storing and querying metrics, logs, and traces through a columnar engine and shared SQL layer. It targets append-heavy, time-indexed workloads such as observability and IoT data, rather than general-purpose transactional database work. Users can query signal tables with SQL and metrics with PromQL. Ingestion options include Prometheus Remote Write, OpenTelemetry OTLP/HTTP, Loki Push API, Elasticsearch Bulk API, InfluxDB Line Protocol, MySQL, PostgreSQL, gRPC, and HTTP. Documented integrations include Prometheus, Grafana, Kafka, Apache Flink, Apache Spark, Telegraf, EMQX, and Fluent Bit. It can run standalone or as a horizontally scalable cluster, with Helm charts, Docker images, and binaries for macOS, Linux, Windows, and Android ARM64. The open-source edition lists username/password authentication, user-level read/write access control, and TLS/SSL connections. Enterprise adds features including LDAP, fine-grained RBAC, audit logging, and encryption at rest. The fully managed Enterprise plan costs $290 a month. Open-source users receive community support through Slack and GitHub.