# QuestDB

> Apache-2.0 low-latency time-series database with SQL

**Category:** Databases  
**Pricing:** open-source  
**URL:** https://questdb.com  
**GitHub:** https://github.com/questdb/questdb  
**Added:** 2026-10-18

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## The Hook

QuestDB is an open-source time-series database for very high ingestion rates: zero-GC Java with C++ and Rust on the hot paths, time-partitioned columnar storage and SQL with time-series extensions.

## What's Good

Apache-2.0 (questdb/questdb), release 10.0.1 (2026-08-24), developed since 2014. Queries run across all cores with SIMD and JIT-compiled filters, storage is tiered (WAL, native columns, Parquet), and data stays open via Parquet, Iceberg and Arrow. It ingests over the InfluxDB line protocol and its own protocol, and speaks the Postgres wire protocol for queries. The project publishes ingestion benchmarks of 19M rows/sec per instance. ★~17.4k.

## The Catch

Benchmarks are the vendor's own. Automatic tiering of cold partitions to object storage, replication and other features are in QuestDB Enterprise; in open source you convert partitions to Parquet yourself. It is built for append-heavy time-series, not general OLTP with frequent updates.

## Verdict

One of the fastest open time-series databases — great for market data and telemetry.