This article reminds me of performance advice I was starting to see in the 2000s decade. Basically it was to not introduce a bunch of pointer heavy data structures to get lower algorithmic complexity. Stuff it all into a vector. You will use some algorithms that the computer science textbook will say it's slower, but if it fits all in cache it doesn't matter. The cache misses following pointers all over town hurts you more.
While this advice isn't wrong, it is misleading. In my benchmarks std::map beats vector after 9 elements. Less than that and linear search is better but branch prediction and cache loading is very good.
Run your own benchmarks on your own data of course. Also map is not considered the best key value store.
I’ve definitely been on teams where they ran the numbers, and found that they were mostly working with smaller containers, and std::vector was the way to go.
If you’re down to that sort of decision-making, you have to measure.
asveikau · · focus · HN ↗
bluGill · · focus · HN ↗
Run your own benchmarks on your own data of course. Also map is not considered the best key value store.
danbolt · · focus · HN ↗
If you’re down to that sort of decision-making, you have to measure.