kdb+ by KX
Ranked 4 of 6 time series databases by recommenders
Fast columnar database and array language used by trading firms for large time-series data. Main caveat: high subscription costs and community edition changes.
Fast columnar database and array language used by trading firms for large time-series data. Main caveat: high subscription costs and community edition changes.
17 people gave an opinion
- recommend it
- 9
- criticize it
- 8
- approval share
- 53%
Recommended in 7 of 13 months
- November 2025: recommended
- December 2025: not recommended
- January 2026: not recommended
- February 2026: recommended
- March 2026: recommended
- April 2026: recommended
- May 2026: recommended
- June 2026: not recommended
- July 2026: recommended
- August 2026: not recommended
- September 2026: recommended
- October 2026: not recommended
- November 2026: not recommended (month in progress)
Why it doesn’t carry the badge
- 9 people recommend itNeeds 10 or more, not met.
- 1.1 recommenders for every criticNeeds 2 to 1 or better, not met.
- Recommended in 7 of 13 monthsNeeds 4 or more, met.
The same three rules apply to every product, and the badge can’t be bought. How the badge works
What people say about it
The reasons people give, with the number of comments that give each one. Open a reason to read what they said.
Why people recommend it
Each mark is one comment
Fast columnar storage for large data
“kdb does two of those by default—columnar and it uses memory mapping (no serialization/deserialization)”
Comment from 9 Apr 2026 in “What Game Engines Know About Data That Databases Forgot” “its array orientation lets it be surprisingly speedy for certain kinds of data crunching”
Comment from 9 Sep 2026 in “The Dataflow Model Revisited” “1bn rows a day is par for the course”
Comment from 4 Jul 2026 in “Designing DB partitions you don't have to babysit” Array language suits time-series logic
“I learned so much from the array semantics about how to concisely represent time-series logic”
Comment from 1 Mar 2026 in “Programming in K” “its array orientation lets it be surprisingly speedy for certain kinds of data crunching”
Comment from 9 Sep 2026 in “The Dataflow Model Revisited” Used by traders and quants
“I used Q with KDB+ for trading and we should ensure to have the right data / calculus as tiny errors might have huge impact ($).”
Comment from 10 Jul 2026 in “A new runtime for k and q: l” “these are the tools that the HFTs and the quants use”
Comment from 23 Nov 2025 in “Ask HN: Good resources to learn financial systems engineering?”
What people warn about
Each mark is one comment
Expensive subscriptions
“are in the customer-squeezing phase of the acquisition”
Comment from 7 Jul 2026 in “A new runtime for k and q: l” “kx.com's current insanely high subscription costs”
Comment from 8 Jul 2026 in “A new runtime for k and q: l” “Possibly also the most expensive?”
Comment from 7 Jul 2026 in “A new runtime for k and q: l” Users growing disillusioned
“I've become disillusioned with kdb.”
Comment from 22 May 2026 in “TorQ: Kdb+ Production Framework” “I've become disillusioned with kdb”
Comment from 22 May 2026 in “TorQ: Kdb+ Production Framework”
Other time series databases people recommend
The four most recommended other time series databases, with the same counts for each, so you can compare like for like. The tick on each bar marks the 2 to 1 line the badge needs.
| Product | Recommend | Criticize | Approval | Months | Owned | Badge |
|---|---|---|---|---|---|---|
| VictoriaMetrics | 26 | 2 | 93% | 12 | — | Approved |
| TimescaleDB | 21 | 11 | 66% | 7 | — | — |
| Grafana Mimir | 12 | 6 | 67% | 5 | — | Approved |
| kdb+ by KXThis page | 9 | 8 | 53% | 7 | — | — |
| RRDtool | 6 | 1 | 86% | 3 | — | — |
What people said
16 of the 17 comments that mention it, newest first. Each links to the original comment.
“its array orientation lets it be surprisingly speedy for certain kinds of data crunching”
“I used Q with KDB+ for trading and we should ensure to have the right data / calculus as tiny errors might have huge impact ($).”
“kx.com's current insanely high subscription costs”
“leaves ~2x perf improvements on the table”
“the people behind it hold values that are typically diametrically opposite of hacker ethos”
“are in the customer-squeezing phase of the acquisition”
“Possibly also the most expensive?”
“KDB does not even qualify on the second requirement”
“1bn rows a day is par for the course”
“they lost too much momentum (and confidence) when back flipping on previous agreements for the community editions”
“I've become disillusioned with kdb.”
“I've become disillusioned with kdb”
“kdb does two of those by default—columnar and it uses memory mapping (no serialization/deserialization)”
“I learned so much from the array semantics about how to concisely represent time-series logic”
“This is certainly pragmatic, although it breaks the math”
“these are the tools that the HFTs and the quants use”
Counts come from 1,795,640 Hacker News comments, November 2025 to November 2026. How we count. Report a mistake.