H2

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): ...