what makes kdb so special and why isn't there an open/libre alternative?
> why isn't there an open/libre alternative?
see here:
The Q Language
21–30 of 161 posts
Re: The Q Language
#22Notes from my KX/kdb experience: 1.) The in-memory DB .exe was around 500 KB. Imagine that. 2.) The Q language syntax, while consistent, is fairly arcane and throwback to decades past. 3.) The documentation and driver support is abysmal. 4.) It's supposedly extremely fast, but I can't help but wonder if this is a lot of successful PR and hype (like hedge fund bosses insisting on Oracle because it's the only db that '…
I used to use KX/kdb/Q/K daily for several years. I wrote a full implementation of reinforcement learning (15 lines), a lightweight MVC framework (to show reports and tables in an internal webapp) and even a Q syntax checker (abusing table as a data structure to hold parse trees). Good or bad, for the longest time, Q was my "go-to" programming language.
Based on that experience...
1) Yes, but that's not huge by modern standard.
2) Q is a DSL version of K. As others have commented, K is a pretty clean implementation of APL, and Q makes K more approachable.
3) I have to agree here, but Q for Mortals makes up for it.
4) It is really fast. As we all know, a vast majority of us actually don't have terabytes and terabytes of data, especially after a reasonably cleanup / ETL / applying common sense. I suppose it helped that I worked in finance, which meant my desktop had 16GB of memory in 2009 and 128GB of memory on a server shared by 4-5 traders.
Finally, Q was never intended for general-purpose computing nor a widespread adoption. At least when I was an active user, the mailing list had the same 20-30 people asking questions and 3-4 people answering them, including a@kx.com (= Arthur Whitney, the creator). Back then, I'd say there were at most 2-3k active users of Q/K in the world. Now that Kx Systems is part of First Derivative and has been working on expanding their customer base, perhaps they have more...?
Re: The Q Language
#23what makes kdb so special and why isn't there an open/libre alternative?
J language is also an open source APL-derivative and offers similar features.
Re: The Q Language
#24This is only software I have ever seen that actually got smaller over time.
Not only that, it is the only software I have ever seen that used a GUI and then ditched it in a subsequent version.
Few programs are so aligned with my own software sensibilities.
Only complaint is that they used to have a FreeBSD port and now only have Linux and macOS but no BSD.
Unfortunately Linux compat in BSD is being perceived by some as a potential security issue these days.
Re: The Q Language
#25Found this illuminating interview with Arthur in the ACM queue: http://queue.acm.org/detail.cfm?id=1531242
Re: The Q Language
#26what makes kdb so special and why isn't there an open/libre alternative?
There’s an open source impl of an earlier version of K: https://kona.github.io/#/ There’s also a JS implementation that aims to implement K6: http://johnearnest.github.io/ok/index.html I don’t believe either implement all the “database” side of kdb+ though. Edit: The J language is similar in some respects, and is GPLed. They've also got a columnar database... http://www.jsoftware.com/jdhelp/overview.html
I'm not aware that kona is working on the speed aspects of K, though, which seems like one of the major reasons to use K.
Re: The Q Language
#27This is only software I have ever seen that actually got smaller over time. Not only that, it is the only software I have ever seen that used a GUI and then ditched it in a subsequent version. Few programs are so aligned with my own software sensibilities. Only complaint is that they used to have a FreeBSD port and now only have Linux and macOS but no BSD. Unfortunately Linux compat in BSD is being perceived by some…
> This is only software I have ever seen that actually got smaller over time.
I agree, this is admirable!
Even if it is under different names (which I think is a far better approach), Sustrik does this too: http://250bpm.com/blog:50 He went from AMPQ (not his own creation) -> ZeroMQ -> nanomsg -> Libmill (essentially Go in C/UNIX style)
Also, OpenBSD comes to mind (LibreSSL for example).
Re: The Q Language
#28Notes from my KX/kdb experience: 1.) The in-memory DB .exe was around 500 KB. Imagine that. 2.) The Q language syntax, while consistent, is fairly arcane and throwback to decades past. 3.) The documentation and driver support is abysmal. 4.) It's supposedly extremely fast, but I can't help but wonder if this is a lot of successful PR and hype (like hedge fund bosses insisting on Oracle because it's the only db that '…
I used to use KX/kdb/Q/K daily for several years. I wrote a full implementation of reinforcement learning (15 lines), a lightweight MVC framework (to show reports and tables in an internal webapp) and even a Q syntax checker (abusing table as a data structure to hold parse trees). Good or bad, for the longest time, Q was my "go-to" programming language. Based on that experience... 1) Yes, but that's not huge by moder…
1) Yes, but that's not huge by modern standard.
OP could have phrased it better, but I presume his point was that 500KB is extremely small by modern standards. The whole executable fits comfortably in L3, so you'll probably never have a full cache miss for instructions. On the other hand, while it's cool that it's small, I'm not sure that binary size is a good proxy for performance. Instruction cache misses are rarely going to be a limiting factor.
Re: The Q Language
#29Not directly related, but Microsoft just released a new language for developing quantum languages, Q#, which doesn't seem to be related at all. I hope this doesn't cause too much confusion.
Re: The Q Language
#30what makes kdb so special and why isn't there an open/libre alternative?
But there are:
k variants:
kona (C, interpreter): https://github.com/kevinlawler/kona
klong (C, interpreter): http://t3x.org/klong/
kuc (C++, JITted): http://althenia.net/kuc
oK (JS, interpreter): https://github.com/JohnEarnest/ok (see also iKe by John Earnest)
cousins:
J (C, interpreter) http://jsoftware.com/
A+ (C, interpreter, unmaintained): http://www.aplusdev.org/index.html
Gnu APL (C, interpreter): https://www.gnu.org/software/apl/
apl.js (JS, interpreter): https://github.com/ngn/apl
There's also NARS2000 and a few other APL interpreters
related:
Numpy and R provide similar functionality, albeit with more verbose (and less fluent) composability. They are usually slower.