DolphinDB vs kdb+

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.

kdb+ is a time-series database and analytics engine from KX, built around the q vector language. It captures and analyzes real-time and historical data for time-sensitive workloads. KX describes in-memory ingestion and analysis with sub-millisecond performance. Its storage layout separates newest in-memory records in an RDB, recent disk data in an IDB, and long-term columnar archives in an HDB. Query options include q and q-SQL, with support for Python, Java, C#, C++, Rust, R, and open-source libraries. Data can arrive through tickerplants, feed handlers, batch mode, TCP/IP, Apache Kafka, or supported programming languages. KX describes applications in trading, fraud detection, and IoT monitoring across Capital Markets, Defense, and High-Tech Manufacturing. Deployments cover Linux, macOS, Windows, APIs, and self-hosted environments, with cloud documentation for AWS, Google Cloud Platform, and Microsoft Azure. SSL/TLS connections use OpenSSL certificates and keys.