Alternatives / Kdb+
Looking for an open source Kdb+ alternative? We compared 5 open source time-series and analytics databases by license, ingestion speed, query language, and maintenance. InfluxDB, QuestDB, and TimescaleDB are the closest, but none uses Kdb+'s q language or matches its niche in trading systems.
Written by Maxime DERAME
Last updated:
| Alternative | Best for | License |
|---|---|---|
| InfluxDB | Time-series SQL with Telegraf | MIT or Apache-2.0 (InfluxDB 3 Core) |
| TDengine | Industrial time-series | AGPL-3.0 |
| TimescaleDB | PostgreSQL extension | Apache-2.0 + Timescale License |
| QuestDB | Fast ingestion with SQL | Apache-2.0 |
| Apache Druid | Streaming OLAP | Apache-2.0 |
We looked for open-source databases for high-volume time-stamped data. We verified each project's license, recent activity, stars, and self-hosting in its repository. See our methodology for the full criteria.
InfluxDB 3 Core is dual licensed MIT or Apache-2.0 and queried with SQL. QuestDB focuses on high ingestion throughput and SQL over the PostgreSQL wire protocol, and TimescaleDB extends PostgreSQL with time partitioning and compression. TDengine adds an industrial historian layer.
Apache Druid is a columnar OLAP database for streaming and batch data with native Kafka and Kinesis ingestion.
TimescaleDB is Apache-2.0 with some features under the Timescale License, TDengine is AGPL-3.0, and InfluxDB keeps clustering in commercial editions. Throughput figures are the vendors' own.
All five had commits within days of this update.
Kdb+ is a proprietary database widely used in finance and priced by license. Open-source databases remove license costs and use SQL, but they are not drop-in replacements for q workloads.
InfluxDB 3 Core is a time series database for real-time ingest and fast queries over event and metrics data, queried with SQL. Its source is dual licensed MIT or Apache-2.0. Features such as clustering are in commercial editions.
Pricing: Free Core edition; commercial editions are paid.
TDengine is an AGPL-3.0 time-series database designed for industrial IoT, with data subscription, stream processing, and connectors for protocols such as MQTT, OPC, and Kafka. Its industrial focus matters if you need a general-purpose tool.
Pricing: Free open-source edition; enterprise and cloud editions are paid.
TimescaleDB is a PostgreSQL extension for time-series data with automatic partitioning, hybrid row and columnar storage, compression of up to 95 percent, continuous aggregates, and about 200 time-series SQL functions. Code outside its tsl directory is Apache-2.0, and the tsl directory is under the source-available Timescale License.
Pricing: Free community edition; managed cloud is paid.
QuestDB is an Apache-2.0 time-series database focused on fast ingestion and fast SQL queries, with the PostgreSQL wire protocol and Grafana and Pandas integrations. Its throughput figures are the vendor's own.
Pricing: Free open-source edition; enterprise features are paid.
Apache Druid is a columnar, time-indexed analytics database for streaming and batch data, handling billions to trillions of rows with millisecond queries, native Kafka and Kinesis ingestion, and automatic schema discovery.
Pricing: Free and open source.
| Alternative | Type | License | Query language | Best for |
|---|---|---|---|---|
| InfluxDB | Time-series DB | MIT or Apache-2.0 (Core) | SQL | Metrics and events |
| TDengine | Time-series DB | AGPL-3.0 | SQL | Industrial IoT |
| TimescaleDB | Time-series DB | Apache-2.0 + Timescale License | SQL | Teams on PostgreSQL |
| QuestDB | Time-series DB | Apache-2.0 | SQL | High-throughput data |
| Apache Druid | Analytics DB | Apache-2.0 | SQL | Real-time analytics |
Want very fast ingestion
QuestDB targets high ingestion throughput and uses SQL.
Want to stay in PostgreSQL
TimescaleDB adds time partitioning and compression to PostgreSQL.
Want a general time-series database
InfluxDB 3 Core is dual licensed MIT or Apache-2.0.