QuestDB

Overview

QuestDB is a time-series database for teams working with fast-moving data and low-latency requirements. It is best suited to technical operators who want to run their own database and query time series with SQL. Its free single-instance edition is capable, but the unencrypted transport and basic authentication make Enterprise the more appropriate choice when security and availability are deployment requirements.

QuestDB advertises ingestion of 8M+ rows per second, a notable target for high-volume pipelines rather than a promise for every workload. The maker says its users span capital markets, digital assets, energy, aerospace, and robotics, and states that it is SOC 2 Type 2 compliant.

Key features

Ingestion and time-series queries

Data can arrive through QuestDB Wire Protocol, InfluxDB Line Protocol, REST API, native client libraries, SQL INSERT, a Kafka connector, or CSV import. This gives teams options for fitting the database into existing ingestion pipelines. Querying combines a vectorized execution engine and standard SQL with SAMPLE BY, ASOF, and HORIZON JOIN, features aimed at time-series analysis rather than a general-purpose database’s most common workloads. Retention policies and horizontal scaling are supported.

Formats and integrations

QuestDB supports Parquet storage and PostgreSQL Wire Protocol compatibility, which can help teams use existing drivers and tools. Its listed integrations include Grafana, Power BI, Apache Kafka, Telegraf, Redpanda, Apache Flink, Pandas, and Apache Spark. That is a useful spread across visualization, ingestion, and data processing.

Deployment and operations

Open Source is self-managed and distributed as binaries, containers, or source code. It is a single-instance edition with community support. Enterprise adds TLS encryption, role-based access control, audit logs, and OAuth 2.0/OIDC single sign-on, as well as replication, automatic failover, and a 99.9% uptime guarantee. It also adds hot storage and Parquet and Iceberg tables on object storage, including Amazon S3, Azure Blob, and GCS, plus dedicated access to QuestDB engineers and guaranteed response-time SLAs. These are substantial operational differences, not minor conveniences: teams needing protected connections, resilient production, or contracted support should not treat the Open Source edition as equivalent.

Pricing

QuestDB Open Source: free. It includes the Apache 2.0 core and self-managed, single-instance deployment with community support. This suits evaluation, development, and deployments that can accept its security and availability limits.

QuestDB Enterprise: custom pricing. It is intended for production deployments and includes replication and failover, RBAC, TLS and SSO, tiered storage, and dedicated support with SLAs. Teams should ask about Enterprise pricing and trial terms before planning a production rollout.

Platforms

QuestDB supports API, Linux, macOS, self-hosted, web, and Windows environments. Its query interfaces include QuestDB SQL, PostgreSQL wire protocol, REST API, and Apache Parquet.

Who it's for

QuestDB is a strong fit for engineering and data teams handling time-series workloads that value low-latency querying, SQL access, and flexible ingestion. Its self-managed free edition is attractive when a single instance and community support are sufficient. For security-sensitive or availability-critical production, Enterprise’s encryption, access controls, failover, uptime guarantee, and support SLAs are more relevant, though custom pricing makes it a less straightforward choice for teams with fixed budgets. Look elsewhere if the single-instance Open Source ceiling or Enterprise’s custom-priced production features do not fit your operating model.

Pros and cons

Pros: Standard SQL, time-series extensions, and PostgreSQL Wire Protocol compatibility can fit familiar query workflows.

Pros: Multiple ingestion methods and integrations with tools such as Grafana, Kafka, and Spark give teams several ways to connect data pipelines.

Pros: The free Apache 2.0 edition is self-managed, and Enterprise adds clear security, resilience, storage, and support capabilities.

Cons: Open Source offers only a single instance and basic authentication over unencrypted transmission, a material restriction for many production deployments.

Cons: Enterprise pricing is custom, so organizations cannot assess its cost from a fixed published rate.

Cons: The Enterprise trial has no stated duration, making it harder to plan a complete evaluation window.

Alternatives

InfluxDB is worth considering if its free, usage-based Cloud Serverless Data In plan or single-node InfluxDB 3 Core better matches the deployment you want; its listed plans include a free plan and trial.

VictoriaMetrics is another freemium option, with open-source single-node and cluster versions if those deployment choices are a priority.

DolphinDB may suit buyers who prefer a perpetual community license with a stated limit of two nodes, two CPU cores, and 8 GB RAM per node.

TDengine is a candidate for teams seeking an open-source TSDB-OSS with clustering capabilities under the AGPL license.

Warp 10 offers a free sandbox for trying the product.

CnosDB, LinDB, and OneTick are also alternatives to compare.

For adjacent categories, see Time-Series Databases, OLAP Databases, Columnar Databases, OLAP Software, and Database Software.

Verdict

Choose QuestDB if your team needs a self-managed time-series database with SQL, broad ingestion options, and a free Apache 2.0 single-instance edition. Its clearest reason to choose Enterprise is the combination of encryption, access controls, failover, and guaranteed support. If those production protections are essential, factor in custom pricing; if single-instance deployment and unencrypted transmission are unacceptable but Enterprise does not suit your budget, look elsewhere.