whichdb
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QuestDB vs TDengine

QuestDB: Columnar time-series SQL database built for market data and very high ingest rates. TDengine: Industrial-IoT time-series database with a table-per-device model and built-in streaming and caching.

key differences

  • Licensing: QuestDB is open source (permissive) (Apache License 2.0 (open source); Enterprise is commercial); TDengine is open source (copyleft) (GNU AGPL v3.0 (open-source edition)).
  • TDengine is built for larger datasets (≤ 1 PB) than QuestDB (≤ 10 TB).
  • Horizontal scaling is none in QuestDB and native in TDengine.
  • Transactions: QuestDB offers limited ACID; TDengine offers none.
  • Only QuestDB has materialized views, online schema changes.
  • Only TDengine has json, pub/sub.

choose questdb for

  • +Market data and order book analytics
  • +Trading and risk dashboards
  • +Industrial and aerospace telemetry
  • +Crypto exchange tick storage

best at · Time-series, Tick data, Real-time analytics

choose tdengine for

  • +Industrial IoT and SCADA historian replacement
  • +Connected-vehicle telemetry
  • +Smart meters and energy grids
  • +Edge-to-cloud sensor data aggregation

best at · IoT, Time-series, Streaming

QuestDBColumnar time-series SQL database built for market data and very high ingest rates.
TDengineIndustrial-IoT time-series database with a table-per-device model and built-in streaming and caching.
overview
Primary model
Time-Series
Time-Series
Also supports
Columnar / OLAP, Relational
Relational
Type
Database engine
Database engine
Status
Active
Active
Developer
QuestDB
TAOS Data
First release
2019
2019
Latest version
10.1.0 (Oct 22, 2026)
3.4.3.3 (Oct 19, 2026)
License
Open source (permissive)Apache License 2.0 (open source); Enterprise is commercial
Open source (copyleft)GNU AGPL v3.0 (open-source edition)
Free tier
✓
✓
popularity
WhichDB Score
34.1
17.4
Rank
#60
#192
GitHub stars
17.5K
25.2K
Stack Overflow questions
282
225
scale & guarantees
Comfortable data size
Medium (≤ 10 TB)
Large (≤ 1 PB)
Horizontal scaling
None
Native
Multi-region
Read replicas
None
ACID
Limited
None
Consistency
Strong
Strong
Schema
Flexible
Strict
Architecture
Single node, Primary replica, Client server
Distributed, Single node, Client server
deployment
Self-hosted
✓
✓
Vendor-managed cloud
✓
✓
Serverless
—
—
Embedded
—
—
Edge
—
✓
Clouds
–
–
capabilities
Transactions
—
—
Joins
✓
✓
Secondary indexes
✓
✓
Full-text search
—
—
Vector search
—
—
Geospatial
—
—
JSON
—
✓
Change data capture
—
—
Triggers
—
—
Stored procedures
—
—
Materialized views
✓
—
TTL / expiry
✓
✓
Pub/Sub
—
✓
Columnar storage
✓
✓
In-memory
—
—
Durable persistence
✓
✓
Compression
✓
✓
Encryption at rest
—
—
Role-based access
✓
✓
Time travel
—
—
Branching
—
—
Online schema changes
✓
—
Streaming ingest
✓
✓
Offline sync
—
—
Runs in WebAssembly
—
—
interfaces
Query languages
SQL
SQL
Client languages
Java, Python, Go, Rust, C, C++, C#, JavaScript
C, Java, Python, Go, Rust, JavaScript, C#
Best for
Time-series, Tick data, Real-time analytics, IoT
IoT, Time-series, Streaming, Real-time analytics
Add more to this comparisonNot sure either fits? Try smart match

QuestDB vs TDengine: FAQ

What is the difference between QuestDB and TDengine?

QuestDB: Columnar time-series SQL database built for market data and very high ingest rates. TDengine: Industrial-IoT time-series database with a table-per-device model and built-in streaming and caching. Licensing: QuestDB is open source (permissive) (Apache License 2.0 (open source); Enterprise is commercial); TDengine is open source (copyleft) (GNU AGPL v3.0 (open-source edition)). TDengine is built for larger datasets (≤ 1 PB) than QuestDB (≤ 10 TB). Horizontal scaling is none in QuestDB and native in TDengine.

When should I choose QuestDB over TDengine?

Choose QuestDB for market data and order book analytics; trading and risk dashboards; and industrial and aerospace telemetry. Choose TDengine for industrial IoT and SCADA historian replacement; connected-vehicle telemetry; and smart meters and energy grids.

Is QuestDB or TDengine more popular?

QuestDB ranks #60 on the WhichDB Score (34.1/100) and TDengine ranks #192 (17.4/100). Popularity is not fit: check the requirements that matter for your project.

Are QuestDB and TDengine open source?

Yes. QuestDB is open source. License: Apache License 2.0 (open source); Enterprise is commercial. Yes. TDengine is open source. License: GNU AGPL v3.0 (open-source edition).