Monday, July 14, 2008

One of 364 000 articles

According to google I've written another one of ~364 000 articles about SQL join types. So the question is why anyone should read it?
Here are a few reasons:

  • It is 25 pages long;

  • It contains join types metamodel or at least my attempt to create one;

  • It tries to describe what are different join types and how they relate to each other;

  • It contains visual pictures of cross, inner, and left, right, full outer joins and this time not with Venn diagramms, which I personally think are suitable for absolutely different operations (set operations);

  • To describe theory it contains 44 examples, which are tested on Oracle, SQL Server and MySQL;

  • It contains several links to other resources.

Because it is 25 pages I've decided not to put it here but it is on my website.

I have one wish though - if You are reading this article and have access to another DBMS (than already mentioned in article i.e. Oracle, SQL Server, MySQL) and have a bit free time, please run examples on your DBMS and post results either here or send me to mail Then I will put them in original article along with contributor's name.

Saturday, July 05, 2008

Latvian Nationwide Song and Dance Celebration in Riga

Today is the beginning of 24th song festival - unique celebration of choral songs, which started 135 years ago with the first song festival. In these times under the rule of Russian Czar, later they continued during the short freedom period as well as even in Soviet times. This year about 35 000 singers and dancers will come to Riga to sing and dance in various concerts. This means more than 2% of all Latvians are coming together to sing and dance and many many more are coming to see them on the concerts or via TV.

Brief history

The first All Latvian Song Festival took place in Riga, year 1873. There were 1003 singers in these times. Under the Russian Czar there were 5 festivals. During the Latvian independence there were 4 festivals and participant count raised to more than 14 000 people. During the Soviet times these festivals partially become the weapon of Soviet propaganda, however these were like two-edged sword, for example, the 100th anniversary of song festival in 1973 was some kind of emotional uprising against Soviet regime. Since 1990 song festivals are held in independent state again and the participant count has raised to impressive more than 2% of all Latvians. The learning process of songs and dances is continued all the time and it is worth to mention that noone pays a single santīms (centime) to participants both for preparation process lasting a few years and also the very festival, although of course there is governmental material support for the organizational purposes of the festival.


During the festival there are many concerts and other kind of events. I'll mention a few of them. The first is participant parade. In the picture below one can look at one of the best choirs in the world "Kamēr", which has won many international awards and also takes part in this festival.
Latvian Song Festival choir Kamēr
The second one is main dance concert. In recent times more than 10 000 dancers are taking part in it.
Latvian Song and Dance Festival
The last and biggest event is the final concert with all the singers in one big choir. It is very impressive moment.
Latvian Song and Dance Festival

Some links