32 bit version of KDB+ is now free for commercial use
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Re: 32 bit version of KDB+ is now free for commercial use
#2For the unindoctrinated, KDB+ is an extremely fast, column oriented, in-memory database. It's based on a language called Q and has been used at many banks to store exchange related data.
Re: 32 bit version of KDB+ is now free for commercial use
#3For the unindoctrinated, KDB+ is an extremely fast, column oriented, in-memory database. It's based on a language called Q and has been used at many banks to store exchange related data.
Syntax is hard to read and easy to make mistakes in considering how it overloads every letter of the alphabet as a command, but the extreme speed pays off I think.
Re: 32 bit version of KDB+ is now free for commercial use
#4This has come up before here, and the recent GNU APL stuff reminded me, but in summary, if you have ever been curious about APL or mildly suspicious of more conventional database approaches you owe it to yourself to take a look at the concepts at work here, especially primacy to columns instead of rows.
The & "where" operator in raw k has stayed with me over the years as a particularly inspired way to deal with column based data.
Re: 32 bit version of KDB+ is now free for commercial use
#5This has come up before here, and the recent GNU APL stuff reminded me, but in summary, if you have ever been curious about APL or mildly suspicious of more conventional database approaches you owe it to yourself to take a look at the concepts at work here, especially primacy to columns instead of rows. The & "where" operator in raw k has stayed with me over the years as a particularly inspired way to deal with colum…
For those of you curious about array-based / columnar programming languages, there's an APL/J/K reddit: http://www.reddit.com/r/apljk
Re: 32 bit version of KDB+ is now free for commercial use
#6Ck out Arthur Whitney's abridged manual for fun:
For using the 32-bit version (from Limits):
22 Limits
Each database runs in memory and/or disk map-on-demand -- possibly partitioned. There is no limit on the size of a partitioned database but on 32-bit systems the main memory OLTP portion of a database is limited to about 1GB of raw data, i.e. 1/4 of the address space. The raw data of a main memory 64bit process should be limited to about 1/2 of available RAM.
Re: 32 bit version of KDB+ is now free for commercial use
#7For the unindoctrinated, KDB+ is an extremely fast, column oriented, in-memory database. It's based on a language called Q and has been used at many banks to store exchange related data.
Syntax is hard to read and easy to make mistakes in considering how it overloads every letter of the alphabet as a command, but the extreme speed pays off I think.
You're incorrect. No individual letters of the alphabet are commands. Every symbol on the keyboard however is an operator (excluding semicolon, braces, brackets, and parens, which operate as line/expression terminators, function definitions, function invocation/array access, and list definitions, respectively).
Re: 32 bit version of KDB+ is now free for commercial use
#8For the unindoctrinated, KDB+ is an extremely fast, column oriented, in-memory database. It's based on a language called Q and has been used at many banks to store exchange related data.
Syntax is hard to read and easy to make mistakes in considering how it overloads every letter of the alphabet as a command, but the extreme speed pays off I think.
It's the same thing I said in the recent J discussion: J (and probably Q) is meant to be read with a help of computer. Reading and writing J consists of incrementally building/decomposing expressions in a REPL. You have wonderful tools to visualize expressions structure in the REPL and you are expected to use them and to experiment with the expressions. You're not supposed to read it as prose, don't even try.
Re: 32 bit version of KDB+ is now free for commercial use
#9Except financial applications what is it good for ?
Re: 32 bit version of KDB+ is now free for commercial use
#10For the unindoctrinated, KDB+ is an extremely fast, column oriented, in-memory database. It's based on a language called Q and has been used at many banks to store exchange related data.
Syntax is hard to read and easy to make mistakes in considering how it overloads every letter of the alphabet as a command, but the extreme speed pays off I think.
There is also an sql like interface in addition to the Q and K languages.
This is probably easier to get started than diving into Q if that is too daunting.