D performance guideline (request)

[Georg Wrede]

Robert Fraser wrote:
> Robert Fraser wrote:
> 
>> - Try using memory-efficient data structures like Judy (
>>   http://judy.sourceforge.net/ ).
> 
> 
> Or maybe not:
> 
> http://www.nothings.org/computer/judy/

Well, the guy certainly saw a lot of effort trying to prove that Judy 
isn't cool. I'm not impressed.

Especially the consistent performance of Judy_seq and Judy_64 was quite 
amazing. If one wants predictable and scalable performance, that 
additionally is excellent, then that is my choice. I assume that, if one 
knows the data is in order, then Judy is good, and for unordered data 
(i.e. that which really needs hashing) a hash is better. (Gee, surprise.)

So, it shows two things: Firstly, if you have a choice, then benchmark, 
benchmark, and benchmark. Don't just read ads or believe the buzz on the 
street. Second, every job has its tool.

IIUC, sparse arrays would be a dream application for Judy, especially if 
they can be filled in order. Or partial order.