QuestDB

QuestDB is an open-source time-series database management system engineered for ultra-low-latency and high-throughput workloads. It is purpose-built for latency-sensitive environments such as trading floors, mission control centers, and real-time analytics in aerospace, defense, energy, and robotics. The database is designed to ingest streaming data at millions of rows per second and query it with standard SQL, making it accessible to AI agents and developers without requiring specialized query languages. QuestDB is written in zero-GC Java and C++ to minimize garbage collection pauses, and its architecture supports a multi-tier storage engine that automatically tiers hot data in memory and cold data to Parquet files in object storage, enabling a unified SQL query surface across both tiers. The platform is deployed at tier-1 firms including Airbus, where it handles billions of data points per day, B3 Exchange for its next-generation Central Securities Depository platform processing over $5 billion in daily traded volume, and BTG Pactual, where it serves as the standard for data aggregation with sub-10ms API response times and support for over 100,000 tickers per table.

QuestDB's key capabilities are backed by specific performance benchmarks. It ingests 8 million rows per second using the InfluxDB Line Protocol, and in published benchmarks it outperforms ClickHouse by 4.1-4.8x on ingestion, 27x on last-point queries, 3.4-4.9x on short-range point lookups, 1.3x on heavy scans, 2.1-2.3x on 12-hour range queries, and 1.2x on some double-groupby aggregations. It supports time-series-specific SQL constructs such as LATEST ON and SAMPLE BY, and its multi-tier storage engine auto-tiers data from hot memory to cold Parquet in object storage (S3, Azure, GCS, NFS, HDFS), with a query planner that spans partitions and Parquet files. The Enterprise edition adds a Rust-based infrastructure layer for high availability with replication and automatic failover, sub-second read replicas across regions, and elastic scaling with storage-compute separation. Security features include TLS, SSO via OAuth 2.0 and OIDC, role-based access control (RBAC), and audit logs, backed by a 99.9% uptime guarantee.

In the time-series database market, QuestDB competes directly with ClickHouse, TimescaleDB, and InfluxDB. Its published benchmarks show significant performance advantages over ClickHouse in ingestion and query speed, particularly for last-point and short-range queries, though ClickHouse may offer broader ecosystem integration and more mature distributed query capabilities. TimescaleDB and InfluxDB are more established in IoT and DevOps monitoring, but QuestDB claims 10x faster ingest than the next-fastest database in its class. The database is also compared to Kdb+, a legacy time-series database from KX, with QuestDB offering a SQL interface that lowers the barrier for adoption. QuestDB is deployed on trading floors and in mission control environments, and its open-source model with a commercial Enterprise tier positions it as a modern alternative to proprietary solutions.

Honest trade-offs exist. A notable limitation is that if any process opens a QuestDB table for writing, no other process—even in read-only mode—can open that table concurrently, which constrains multi-process architectures. The database is optimized for time-series workloads and may not be ideal for general-purpose OLTP or complex relational queries. The Enterprise edition, which provides high availability, elastic scaling, and SLA-backed support, requires a paid subscription starting at $65 per month, while the free version lacks replication and failover. The community edition is lightweight and designed to work out of the box, but users may need to invest in operational expertise for large-scale deployments, particularly when integrating with object storage and managing tiered storage policies. Finally, while QuestDB supports SQL and Parquet for data portability, its ecosystem of connectors and integrations is smaller than that of more mature databases like ClickHouse or InfluxDB.

Free version available with community support. Paid plans start at $65 per month for Enterprise edition, which includes high availability, replication, SSO/RBAC, tiered storage, and SLA-backed support. Free trial available.