QuestDB vs SelectDB

QuestDB is a time-series database for environments where low latency matters, including mission-critical workloads. It supports standard SQL through a vectorized execution engine, along with time-series extensions such as SAMPLE BY, ASOF, and HORIZON JOIN. QuestDB advertises ingestion speeds of 8M+ rows per second. The Open Source edition is self-managed and available as binaries, containers, or source code; it is single-instance and supports Parquet storage and PostgreSQL Wire Protocol compatibility. Ingestion options include QuestDB Wire Protocol, InfluxDB Line Protocol, REST API, native client libraries, SQL INSERT, Kafka connector, and CSV import. Listed integrations include Grafana, Power BI, Apache Kafka, Telegraf, Redpanda, Apache Flink, Pandas, and Apache Spark. Open Source costs nothing and includes community support. Enterprise adds security controls, replication, automatic failover, object-storage tables, and dedicated support with response-time SLAs.

SelectDB has no write-up on Specifiction yet; its figures are above.