Difficulty level 3 of 5: Intermediate
Today I read the What Goes Around Comes Around chapter from the “Red Book” by Michael Stonebraker and Joseph M. Hellerstein. The chapter (or paper if you will) is a summary of 35 years of data model proposals, grouped into…
Knowing a lot about something, makes me more prone to appraising its value. I unfortunately know very little about Linked data. For this reason, I’ve had a very biased and shamefully low opinion about the concept of linked data. I’ve…
This is my base pattern for writing a parser in Python by using the pyparsing library. It is slightly more complicated than a hello world in pyparsing, but I think it is more useful as a small example of writing…
Gratefully making use of what others have provided, i.e. geopy, Google and plpythonu. Type to hold result of geocoding: CREATE TYPE geocoding AS ( place text, latitude double precision, longitude double precision ); Function that does the actual geocoding (to…
Today I watched a video on RAMCloud. I have made an index over the various sections of the video, with direct links. You’ll find this index in the bottom of this post. “The RAMCloud project is creating a new class…
The profiling tool in GNU is called gprof. Here is a short, boring example of how to use it. 1) Write hello world in C (hello.c) < pre lang=”c”> #include <stdio.h> int foo() { int b = 54324; int j;…
To time the execution of various stages of a long transaction, I’m using the following function: CREATE OR REPLACE FUNCTION CVL_TimerLap() RETURNS double precision AS $$ import time now = time.time() if not SD.has_key(‘t_last’): SD[‘t_last’] = now elapsed = now…
Simple. This works.
OK, calling it a benchmark is a bit of an overstatement. It’s taking two different database libraries for a quick spin, and seeing how fast they can write a bunch of integers to disk. A second benchmark checks how fast…
In a project I’m going to use clustering algorithms implemented in Python, such as k-means. Clustering scipy.cluster has been reported to have some problems, so for now I’ll use PyCluster (following advice given on stackoverflow). Install PyCluster: pip install…