Watched the RAMCloud video
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…
kostas
How many requests per second can I get out of Redis?
Warning: This is not a very interesting post. I’m toying around with the Redis benchmarking tool. What would be significantly more interesting would be to toy around with the Lua API in Redis, which I’ll do in a subsequent post.…
Hello GNU profiling
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) #include int foo() { int b = 54324; int j; for (j=0; j <…
A stop watch for Postgres
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 $$ import time now = time.time() if not SD.has_key(‘t_last’): SD[‘t_last’] = now elapsed = now…
DIKU APL Group IRC channel
Come join the DIKU APL channel on IRC:
Running LP-solver in Postgres
Having reinstalled PostgreSQL with support for Python and pointing at my non-system python, it is time to test whether I can use the convex optimizer library I’ve installed in my Python 2.7 (pip install cvxopt). Install PL/Python if not already…
Some good slides for using PostgreSQL with Python
Peter Eisentraut has written some good slides on coding PostgreSQL clients in Python and on using Python as a stored procedures language in PostgreSQL. First half deals with using Python as a Postgres client. Second half deals with coding stored…
A new side to Bill Gates
I don’t know why, but I really liked to read this post by Bill Gates. In an odd way it was heart warming :-) Three Things I’ve Learned From Warren Buffett Maybe I should start reading Bill Gates blog as…
Make a RAM disk on Mac OS X 1.5 or later
Create the RAM disk: diskutil erasevolume HFS+ “ramdisk” `hdiutil attach -nomount ram://1165430` (the magic number 1165430 is explained here as the number of 512 byte sectors. The string “ramdisk” is just the name of the disk, which will appear under…
Calling a Python LP-solver from a PostgreSQL function
Prepare the database by installing PL/Python and a function: CREATE EXTENSION IF NOT EXISTS plpythonu; CREATE OR REPLACE FUNCTION hello_lp() RETURNS float[] AS $$ import subprocess output = subprocess.Popen ( [ “”, “” ], stdout = subprocess.PIPE, stderr = subprocess.STDOUT…