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This post has some overconfident and under-researched claims: > This came about because last year I wrote the fastest hash table (I still make that claim) I'm
by jbapple 8y ago
This post has some overconfident and under-researched claims:
> This came about because last year I wrote the fastest hash table (I still make that claim)
I'm extremely dubious of claims of the "fastest $DATA_STRUCTURE" without qualifiers about workload, hardware, and time/space trade-off. In particular, the last graph of this post shows some workloads (400k int keys, int[16] values, unsuccessful lookups) where the author's implementation of Swiss Table (as Google called their table) is 3x-10x slower than "bytell_hash_map", the author's own design.
> google_flat16_hash_map. This last one is my implementation of Google’s new hash table. Google hasn’t open-sourced their hash table yet, so I had to implement their hash table myself. I’m 95% sure that I got their performance right.
The talk announcing Swiss Table clearly didn't have enough detail to fully replicate their results. This 95% claim is rather astonishing in light of that.
- coconutrandom 8y agometa: classic HN, top post is a Negative Nancy regardless of how impressive the new thing is. Is there a name for this phenomena yet?
- hobofan 8y ago"Critical thinking"?
- vanderZwan 8y agoI know the type of post you talk about - dismissive easy critiques like "correlation does not.." - but GP's remark is not quite like that: - it states the article has some overconfident claims. - it gives detailed arguments for why > Is there a name for this phenomena yet? "bachelors' wives and maidens' children are well taught"?
- nabla9 8y agoNo and there should not be. There unjustified critique and justified critique. ´
- newnewpdro 8y agoA healthy dose of skepticism
- general_pizza 8y agoHmm I’m seeing the opposite. The last graph shows Google’s hash table outperforming in all but a few places, including at 400k. Perhaps you mixed the axes up, lower is better here. I also just want to comment that skepticism to high claims is good but your comment seems a bit too harsh. Briefly looking at his post where he goes into his “fastest hash table” it’s quite long, very detailed and has similar graphs. That doesn’t seem under-researched to me.
- jbapple 8y ago> Hmm I’m seeing the opposite. The last graph shows Google’s hash table outperforming in all but a few places, including at 400k. You're exactly right, General Pizza. I was trying to say that the Google table was faster, even though the author claimed that his or her table was "fastest" without qualification. Thanks for pointing that out; I'll leave my post as it is so yours continues to make sense in context.