whichdb
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DolphinDB vs kdb+

DolphinDB: Distributed time-series database and scripting platform for quant finance and industrial analytics. kdb+: Column-store time-series engine with the q language, a fixture of capital-markets tick data.

key differences

  • Horizontal scaling is native in DolphinDB and manual in kdb+.
  • Only DolphinDB has transactions, role-based access.
  • Only kdb+ has json, encryption at rest.

choose dolphindb for

  • +Quant research and factor computation
  • +Real-time market data processing
  • +Trading risk and surveillance
  • +Industrial IoT analytics with streaming rules

best at · Tick data, Time-series, Streaming

choose kdb-plus for

  • +Equities, FX and futures tick capture
  • +Trade surveillance and best-execution analysis
  • +Quant research on historical market data
  • +Real-time risk and P&L

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

DolphinDBDistributed time-series database and scripting platform for quant finance and industrial analytics.
kdb+Column-store time-series engine with the q language, a fixture of capital-markets tick data.
overview
Primary model
Time-Series
Time-Series
Also supports
Columnar / OLAP, Relational
Columnar / OLAP, Relational
Type
Database engine
Database engine
Status
Active
Active
Developer
DolphinDB Inc.
KX
First release
2018
2003
Latest version
3.00.6.1 (Sep 2026)
KDB-X 5.0.20261015 (Oct 15, 2026)
License
ProprietaryCommercial (free community edition with limits)
ProprietaryCommercial; KDB-X Community Edition free with resource limits
Free tier
✓
✓
popularity
WhichDB Score
11.6
31.8
Rank
#281
#75
GitHub stars
–
–
Stack Overflow questions
–
2.3K
scale & guarantees
Comfortable data size
Large (≤ 1 PB)
Large (≤ 1 PB)
Horizontal scaling
Native
Manual
Multi-region
None
None
ACID
Limited
Limited
Consistency
Strong
Strong
Schema
Strict
Strict
Architecture
Distributed, Single node, Client server
In memory, Single node, Client server
deployment
Self-hosted
✓
✓
Vendor-managed cloud
—
✓
Serverless
—
—
Embedded
—
—
Edge
—
—
Clouds
–
AWS
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, DolphinDB script
q, qSQL, Python (PyKX)
Client languages
Python, C++, Java, C#, Go, JavaScript
Python, Java, C, C#
Best for
Tick data, Time-series, Streaming, Real-time analytics
Tick data, Time-series, Real-time analytics, Streaming
Add more to this comparisonNot sure either fits? Try smart match

DolphinDB vs kdb+: FAQ

What is the difference between DolphinDB and kdb+?

DolphinDB: Distributed time-series database and scripting platform for quant finance and industrial analytics. kdb+: Column-store time-series engine with the q language, a fixture of capital-markets tick data. Horizontal scaling is native in DolphinDB and manual in kdb+. Only DolphinDB has transactions, role-based access. Only kdb+ has json, encryption at rest.

When should I choose DolphinDB over kdb+?

Choose DolphinDB for quant research and factor computation; real-time market data processing; and trading risk and surveillance. Choose kdb+ for equities, FX and futures tick capture; trade surveillance and best-execution analysis; and quant research on historical market data.

Is DolphinDB or kdb+ more popular?

kdb+ ranks #75 on the WhichDB Score (31.8/100) and DolphinDB ranks #281 (11.6/100). Popularity is not fit: check the requirements that matter for your project.

Are DolphinDB and kdb+ open source?

No. DolphinDB is proprietary, closed-source software. License: Commercial (free community edition with limits). No. kdb+ is proprietary, closed-source software. License: Commercial; KDB-X Community Edition free with resource limits.