Database

Oracle and Sun announced a few days ago that Oracle will buy Sun. Others are more apt than me to comment on the financial and strategic impacts of this move (for example, in the Guardian, the New York Times, the Wall Street Journal or on Slashdot). I’m more interested in the potential implications this move could have on some Open Source projects which were backed by Sun. I indeed believe Oracle will continue the development of his contributions to Open Source software, whether they are notable ( Btrfs or Oracle Enterprise Linux) or less visible. ...

If you live in Belgium, you probably noticed a small bu zz about a database police is building about Belgian citizens and, more precisely, about the access control of this database. The “problem” is that this database already exists and it has a legal basis since … 1998 (10 years!). But mainstream media won’t tell you that (or I’m unaware of it). I don’t think there is a conspiracy. It’s just that, sadly, the current economic environment doesn’t leave much space for this kind of information. The Minister of Justice’s website has more info on this database and its content (excerpt of translation below): ...

Following a comment from Alexandre on a previous post, I went a little bit further with my performance test of database engines running under Java. This evening, I tested a profiling tool and a variable number of insertions/retrievals (I didn’t tested transaction). Taking the code from the previous time, I simply changed the number of elements to be inserted/retrieved. As expected, the durations of object initialization (except for 2 points for Derby and H2) and database creation did not change with the number of elements to be inserted, Derby being still the slowest engine to create a simple database (1 table only). The durations of the insertion step increased slowly with all the database engine, except for SQLite+JDBC: you can see a much steeper initial angle in the increase of the duration in the graph below (be careful: x-axis shows logarithmic values). ...

Following a comment from Alexandre on a previous post, I included SQLite in my performance test of database engines running under Java. What prevented me from using SQLite in the previous test is that it’s not a pure Java database and one have to use third-party JDBC driver and implementation classes in order to manage this database engine. IMHO, I also dislike another fact: SQLite does not enforce data type constraints ( and it’s a feature, not a bug) so everything is stored as ASCII string, even if you have very few other “artificial” data types. ...

I’m wondering why Sun chose Derby for its JavaDB … I used JavaDB on a project and my main reason was that it’s embedded in the last Java Runtime Engine (JRE). But I saw a clear degradation of performances (my main criteria is speed) when I had to access the embedded database. And it became worst when I ran my project from a CD-ROM (because it has to be distributed). So I decided to run a small, rough test and compare JavaDB with two other free Java database engines: H2 and HSQLDB. And the results are astonishing: JavaDB seems to be the slowest, hence the worst choice (except for the license). Here are the results (click to show the normal size graphs): ...