Second, I have independently invented this (quicksort on string prefixes) at my time at CWI, although I didn't end up publishing it, because...
Third, this was already published in the original 1961 Quicksort paper by Hoare: https://www.cs.ox.ac.uk/files/6226/H2006%20-%20Historic%20Qu.... Near the end, the section on "Multi-word keys" describes a quicksort that partitions on just the first word, and only accesses the next word for the equality partition. And funnily enough this paper credits P. Shackleton for this, thus this idea was thought of even before the Quicksort paper came out.
So as is usual for software patents, this patent never should have been awarded.
It's kind of insane that such an obvious optimization can be patented, I have to imagine that it has been invented independently dozens if not hundreds of times.
> A CPU register is naturally 8 bytes in size, and if Oracle extracts 8 bytes from two strings for comparison, then the comparison requires fewer registers and fewer CPU cycles.
Isn't this just a typical SIMD optimization that tons of projects use?
Nothing in this slop means anything particularly, but this detail is extra-wrong considering the variety of processors that the inventor says he used to create this algorithm.
First, this article is mostly (AI?) regurgitation. This is much better: https://smalldatum.blogspot.com/2026/01/common-prefix-skippi....
Second, I have independently invented this (quicksort on string prefixes) at my time at CWI, although I didn't end up publishing it, because...
Third, this was already published in the original 1961 Quicksort paper by Hoare: https://www.cs.ox.ac.uk/files/6226/H2006%20-%20Historic%20Qu.... Near the end, the section on "Multi-word keys" describes a quicksort that partitions on just the first word, and only accesses the next word for the equality partition. And funnily enough this paper credits P. Shackleton for this, thus this idea was thought of even before the Quicksort paper came out.
So as is usual for software patents, this patent never should have been awarded.
It's kind of insane that such an obvious optimization can be patented, I have to imagine that it has been invented independently dozens if not hundreds of times.
that article sucks and doesnt describes real algorithm
I think this is inventors blog https://smalldatum.blogspot.com/2026/01/common-prefix-skippi...
Oh this is much more novel (comparatively), that makes a lot more sense. Kind of an amalgamation of a bunch of optimizations.
Thanks for sharing.
[+1] this was a good read
patent: https://patents.google.com/patent/US7680791B2
Looks like an AI rewrite of something better.
Thank you.
For wasting my time.
The only thing someone could learn from this is that CPU registers can be 8 bytes.
A vague article.
With one sentence per line.
Most annoying.
> A CPU register is naturally 8 bytes in size, and if Oracle extracts 8 bytes from two strings for comparison, then the comparison requires fewer registers and fewer CPU cycles.
Isn't this just a typical SIMD optimization that tons of projects use?
>A CPU register is naturally 8 bytes in size
What does naturally even mean here. How is a 64 byte register's (zmm0) size any less natural?
Or a 7 byte register, if you really want to get freaky.
What about 36 bit registers
Nothing in this slop means anything particularly, but this detail is extra-wrong considering the variety of processors that the inventor says he used to create this algorithm.