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RobinL • today at 2:27 PM • 3 replies • view on HN

We've found DuckDB 2.0 to be way faster on high core count machines on EC2. Not just reading data from S3, but the actual computations too. Much more likely to see 100% utilisation up to about 128vCPUs or 192vCPUs, and that CPU usage to translate into workloads completing faster.

Still don't usually see a speedup past about 192vCPU, but prior to 2.0, speed would top out at more like 64vCPU, so this is a big win.

That has enabled us to scale Splink (FOSS record linakge software) to process 1bn records with 10bn record comparisons in 10 mins, which as far as I'm aware makes it the fastest linkage engine of this kind. Most of this performance comes from simply delegating the big calculations to the DuckDB engine! https://moj-analytical-services.github.io/splink/topic_guide...

Thanks to the team for all their work!


Replies

gopalv • today at 4:56 PM

> Not just reading data from S3, but the actual computations too.

Async io generally causes a CPU bump as a side-effect, when the bottleneck moves from the disk to the CPU (more usually memory bandwidth).

My experience is from a different SQL engine, but the improvement in scan rates directly translates all other operators getting more work to do per unit time.

More CPUs pegged at 100% is always a good sign of smooth flows, but optimizing further requires data layout changes from that point. Even if it is a sub-linear speedup out of concurrency scaling - more with more is still a win, assuming you can pay for more (the Dy-skew paper has an example I can quote).

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dicey • today at 3:26 PM

I’m a huge fan of splink - and how you’ve been able to adopt duckdb.

Do you find that with the performance of duckdb, you see large deployments of spark based workflows less often? It seems hard to justify the complexity of spark if you can use duckdb , but I’m wondering if you see end users still reach for spark for any reasons?

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