# kdb+ by KX

9 Hacker News commenters recommended kdb+ by KX and 8 criticized it, November 2025 to November 2026. It was recommended in 7 of 13 months.

**Verdict:** Fast columnar database and array language used by trading firms for large time-series data. Main caveat: high subscription costs and community edition changes.

## Why people recommend it

- Fast columnar storage for large data (3 comments): "kdb does two of those by default—columnar and it uses memory mapping (no serialization/deserialization)" ([source](https://news.ycombinator.com/item?id=47708847)) "its array orientation lets it be surprisingly speedy for certain kinds of data crunching" ([source](https://news.ycombinator.com/item?id=49628149)) "1bn rows a day is par for the course" ([source](https://news.ycombinator.com/item?id=48787154))
- Array language suits time-series logic (2 comments): "I learned so much from the array semantics about how to concisely represent time-series logic" ([source](https://news.ycombinator.com/item?id=47211443)) "its array orientation lets it be surprisingly speedy for certain kinds of data crunching" ([source](https://news.ycombinator.com/item?id=49628149))
- Used by traders and quants (2 comments): "I used Q with KDB+ for trading and we should ensure to have the right data / calculus as tiny errors might have huge impact ($)." ([source](https://news.ycombinator.com/item?id=48863019)) "these are the tools that the HFTs and the quants use" ([source](https://news.ycombinator.com/item?id=46027293))

## What people warn about

- Expensive subscriptions (3 comments): "are in the customer-squeezing phase of the acquisition" ([source](https://news.ycombinator.com/item?id=48823483)) "kx.com's current insanely high subscription costs" ([source](https://news.ycombinator.com/item?id=48832969)) "Possibly also the most expensive?" ([source](https://news.ycombinator.com/item?id=48823468))
- Users growing disillusioned (2 comments): "I've become disillusioned with kdb." ([source](https://news.ycombinator.com/item?id=48241256)) "I've become disillusioned with kdb" ([source](https://news.ycombinator.com/item?id=48239967))

## Alternatives hackers recommend

- [VictoriaMetrics](https://hackerapproved.com/p/victoriametrics.md): 26 recommend
- [TimescaleDB](https://hackerapproved.com/p/timescaledb.md): 21 recommend
- [Grafana Mimir](https://hackerapproved.com/p/mimir.md): 12 recommend
- [RRDtool](https://hackerapproved.com/p/rrdtool.md): 6 recommend
- [InfluxDB](https://hackerapproved.com/p/influxdb.md): 5 recommend

## Where to get it

- [Visit the official site](https://kx.com/)

## Cite as

Hacker Approved, "kdb+ by KX", https://hackerapproved.com/p/kdb-plus/ (counts from 1,795,640 Hacker News comments, November 2025 to November 2026).