Monday 29 November 2010

PostgreSQL Installing screencast

PostgreSQL Installing

Video (1:52)
Video (OGV, no sound) [5,3M]

Subtitles
Subtitles (SRT, UK, UTF-8) [2,8K]
Subtitles (SRT, EN, UTF-8) [1,9K]

Start playing in mplayer
Video-only:
mplayer PostgreSQL_Installing.ogv
UK-subs:
mplayer PostgreSQL_Installing.ogv -sub PostgreSQL_Installing.uk.srt -subcp utf8
EN-subs:
mplayer PostgreSQL_Installing.ogv -sub PostgreSQL_Installing.en.srt

Sunday 21 November 2010

Wonderfull 200 lines patch for Linux Kernel

Soon, in Linux kernel 2.6.38 will be applied patch, that will improve Linux desktop responsiveness. It means, that you can watch video and roll pages in web-browser fluently.

Patch was written by Mike Galbraith. It adds only 223 lines of code into Linux Kernel.

Look like, Linus Torvalds liked it (and write about it in his e-mail):

Yeah. And I have to say that I'm (very happily) surprised by just how small that patch really ends up being, and how it's not intrusive or ugly either.

I'm also very happy with just what it does to interactive performance. Admittedly, my "testcase" is really trivial (reading email in a web-browser, scrolling around a bit, while doing a "make -j64" on the kernel at the same time), but it's a test-case that is very relevant for me. And it is a _huge_ improvement.

It's an improvement for things like smooth scrolling around, but what I found more interesting was how it seems to really make web pages load a lot faster. Maybe it shouldn't have been surprising, but I always associated that with network performance. But there's clearly enough of a CPU load when loading a new web page that if you have a load average of 50+ at the same time, you _will_ be starved for CPU in the loading process, and probably won't get all the http requests out quickly enough.

So I think this is firmly one of those "real improvement" patches. Good job. Group scheduling goes from "useful for some specific server loads" to "that's a killer feature".

Linus

Web-site phoronix.com created two videos: with sched_autogroup_enabled and without:


sched_autogroup_enabled=0


sched_autogroup_enabled=1

Wednesday 17 November 2010

Small Binomial Distribution lib

Here is my lib, writed for educational purposes.

You may download repo from GitHub page of lib
or using this git-link: git://github.com/dector/Binomial-Distribution.git

For visualisation project uses JFreeChart lib, what you can download from JFreeChart download page.

Screenshots:
n = 100
p = 0.5

n = 1000
p = 0.7

n = 5000 ;)
p = 0.3

Enjoy!

Presentations for "Relational databases"

Relational databases
Air date: 8.11.2010
OpenDocumentPresentation (.odp) [2.0 MB]
Portable Document Format (.pdf) [2.6 MB]

Relational algebra
Air date: 15.11.2010
OpenDocumentPresentation (.odp) [277 KB]
Portable Document Format (.pdf) [376 KB]