Derby aka JavaDb is the slowest

I am into an interesting experiment on using multiple open source dbs for my current assignment. The requirement is to come up with a data mashup simillar to Apatar (but not as sophisticated as that). Though Apatar is an open source and code is available for public, the need of the hour is to complete the data mashup within a week of time and that too customized and another key thing was Apatar uses Derby db which is very slow.

Now, back to the point, this required me to test the code with various open source databases to show the client about the performance of each database.

I initially tested it with mysql. But then I thought we need an embedded database so that the deployment of this application would be easier. I investigated few sites and got through handful of new open source dbs like SmallSQL, H2, HSQL, Derby, PostGreSQL, axiom etc.

Due to time constraint, I chose to test the app's performance with few databases like Derby, H2, HSQL, mysql (though mysql is not an option for me).

Here is the matrix (showing the execution time in seconds) after I test. My test was
1. To creating 3 tables
2. Inserting 20000 records into them
3. To create indexes
4. Joining them and building expressions and produce the output.

With 2 tables with 20K records
MySQL - 34
Derby - 183
HSQL - 7.67
H2 - 9.45

With 3 tables with 20K records
MySQL - 53
Derby - 604
HSQL - 13.47
H2 - 14.36

To my surprise, HSQL is better than even H2.