Archive Page 3

kdb standard SQL support s)

First, in case you haven’t heard about it kdb has a standard SQL mode, you can send queries prefixed with s) and they will be interpreted as standard SQL like so:

Notice how the standard “and” syntax worked when I used s) but without it, q’s right to left evaluation causes problems. It’s about now that a lot of people get very excited, they think great I can skip learning that q-sql and use my standard SQL. Sometimes the look of joy on their faces transforms to frustration once they start using it. So let’s look at what works:

Operation Works?
Standard SQL Inserts Yes
ORDER BY half works
COUNT Yes
DELETE Yes
UPDATE Yes
String matching slightly works
NOT NO
IN Yes
GROUP BY Yes
LIMIT / TOP NO
Date Times NO

Standard SQL Inserts work

ORDER BY half works

“ORDER BY” will sort the columns in ascending order, attempting to use DESC has no effect.

COUNT works

DELETE works

UPDATE works

String matching slightly works

NOT fails

Modifying our String query slightly by adding NOT throws an error. My guess is that the interpreter has got confused.

IN works

GROUP BY works

LIMIT / TOP does not work

Date Times Don’t Work Right

Overall standard SQL support in kdb has got much better. However I would still recommend only using the s) syntax for plugging into an existing jdbc/odbc visualization tool and getting some immediate simple results. For any form of complex queries on strings, joins etc. support is either not there or the result may not be what you expect.

qStudio kdb IDE 1.40 Released

qStudio 1.40 is now available to download.

The latest changes include:

  • No need to save changes before shutdown, unsaved changes stored till reopened.
  • Add sqlchart to system path.
  • Fix display of tables with underscore in the name.
  • Database documenter/report enhancements
  • Improved code printing
  • FileTreePanel much more efficient at displaying large number of files.

Julia Programming Language

Julia programming language is being touted as the next big thing in scientific programming. It’s high-level like R/Python but meant to be much faster due to its smart compiler. I’ve been giving it a bit of a tryout, as part of learning it I’ve generated a list of all julia functions and will be creating examples for some of the more popular ones.

KX closes down commercial 32 bit kdb, open alternatives?

Previously on our blog we had a lively debate about a possibly Open Sourced kdb+ , unfortunately kx now seems to be moving the opposite direction. In a recent announcement they are now restricting “32-bit kdb+ for non-commercial use only”. The timing is particularly unfortunate as:

Alternative (far less enterprise proven) solutions are available:

  • MAN AHL have released Arctic an open source Market Data platform based on python and MongoDB
  • Kerf Database – A DB aimed at the same market as kdb has now partnered with Briarcliff-Hall and is making greater sales inroads

This renewed interest in kdb alternatives hasn’t so far delivered a kdb+ killer but I fear in time it will.

kdb+ Twitter Data Feed Now Open Sourced

Free kdb+ Twitter Feedhandler

twitter-kdb-logo

Previously we showed a demo of us getting data from twitter into kdb, we are now open sourcing part of that work, allowing you to quickly get some real social data into kdb to play with.

If you want to try running the kdb twitter data feed visit our https://github.com/timeseries and see the twitter-kdb project. You can even download the jar straight from our releases page. Here’s an image of the command line version running:

twitter-kdb

You will need to setup API keys for twitter

kdb code highlighting in intellij

An intellij keyword file is now available to provide syntax highlighting of kdb code in intellij:

q Code Intellij Highlighting

q Code Intellij Highlighting

To install it copy this xml file to this directory:
C:\Users\USERNAME\.IdeaIC14\config\filetypes
Where USERNAME is obviously your username. Then restart intellij and open a .q file.

We’ve updated our notepad++ qlang.xml to provide code folding and highlighting of the .Q/.z namespaces.

kdb qunit testing now open source on github

We’ve now posted all source code from this website on our github kdb page.

Additionally we are open sourcing qunit, our kdb testing framework.
We look forward to receiving pull requests to fix our (hopefully few) bugs.

qStudio adds Nested Server Folder Support

Since our last qStudio kdb+ IDE announcment we have added a lot of new features:

Bulk importing kdb server lists

Bulk importing kdb server lists

There’s a lot of new features to allow supporting a huge number of servers efficiently:

  • Support importing HUGE number of servers:
    • 5000+ server connections are now supported
    • To prevent massive memory use, the object tree for a server is no longer refreshed at startup only on connection.
    • Allow specifying default username/password once for all servers
    • Allow nested connection folders
    • Add critical color option – servers with prod in name get highlighted in red
  • Sort File Tree Alphabetically
  • Numerous bugfixes including:
    • Fix critical Mac bug that prevented launching in some instances
    • Fix query cancelling

Smart Meter Data Analytics Benchmark – Open vs Closed

Benchmarking Smart Meter Data Analytics – I got forwarded this interesting paper that compares how quickly smart meter data can be analysed using

  1. a Relational Database
  2. Matlab
  3. An in-memory Column-Oriented database
  4. Two new NoSQL alternatives

Smart electricity grids, which incorporate renewable energysources such as solar and wind, and allow information sharingamong producers and consumers, are beginning to replace conventional power grids worldwide. Smart electricity meters are afundamental component of the smart grid, enabling automated collection of fine-grained (usually every 15 minutes or hourly) consumption data. This enables dynamic electricity pricing strategies,in which consumers are charged higher prices during peak timesto help reduce peak demand. Additionally, smart meter data analytics, which aims to help utilities and consumers understand electricity consumption patterns, has become an active area in researchand industry. According to a recent report, utility data analytics isalready a billion dollar market and is expected to grow to nearly 4billion dollars by year 2020

 

Open Sourced kdb+

In a world overran with open source big data solutions is kdb+ going to be left behind? I hope not…

Every few weeks someone comes to me with a big data problem often with a half-done mongoDB/NoSQL solution that they “want a little help with”. Usually after looking at it I think to myself

“I could solve this in 20 minutes with 5 lines of q code”

But how do I tell someone they should use a system which may end up costing them £1,000s per core in licensing costs. Yes it’s great that there’s a free 32-bit trial version but the risk that you may end up needing the 64-bit is too great a risk.

kdb+ vs mongoDB database popularity

Given the ever-increasing number of NoSQL solutions and in particular the rising popularity of Hadoop, R, python and MongoDB it’s not hard to see that open-source is taking over the world. Right now kdb+ still has the edge, that it’s faster, sleeker, sexier..but I don’t think that will save it in the long run. The power of open-source is that it let’s everyone contribute, witness the 100’s of libraries available for R, the 1000’s of javascript frameworks. The truly sad thing is that it’s not always the best underlying technology that wins. A 1000 amateurs creating a vibrant ecosystem of plug-ins, add-ons, tutorials… can beat other technologies through sheer force of numbers.

  • APL was a great language yet it remains relegated to history while PHP flourishes.
  • PostgreSQL was technically superior to MySQL yet MySQL is deployed everywhere

I believe kdb+ is the best solution to a large number of “big data” problems (small data to kdb+), When you stop and think, time-series data is everywhere, open sourcing kdb+ would open up entirely new sectors to kdb+ and I hope it’s a step kx take before it’s too late.

What do you think? Leave your comments below.