Hi Tobias, first of all, welcome on jena-users mailing list. Tobias Willig wrote: > Hi everyone, > > I like to add support for MonetDB in SDB and I have two questions concerning > this project: > > 1. How much effort it takes to add support for a new database type?
It requires some effort. You need to add new Java classes and the necessary tests. Have you checked out the SDB sources yet? If not: svn co https://svn.apache.org/repos/asf/incubator/jena/Jena2/SDB/trunk/ SDB cd SDB mvn test You can use Eclipse and search for "Derby" which is one of the DBMS supported by SDB. This way you'll find the list of Java classes in SDB to support Derby. Then, you can read and study those classes. While you do that, you'll learn the design of SDB and you will get an idea on what it is required to add MonetDB. > 2. Are there predefined extension points that allow adding a new database > type easily? Yes, there are. Look at the super classes and interfaces from the list of classes above (i.e. searching for "Derby"). There isn't an "how to add a new database to SDB" guide, however make sure you read the general SDB documentation (it does not hurt). Also, if you want to contribute an "how to add a new database to SDB" you are more than welcome to do so. > If so could you give me the name of some classes and config files, which > are important to accomplish that task? You can start from: GenerateSQLDerby -- extends --> GenrateSQL FormatterSimpleDerby -- extends --> FormatterSimple StoreSimpleDerby -- extends --> StoreBase1 FmtLayout2HashDerby -- extends --> FmtLayout2 StoreTriplesNodesHashDerby -- extends --> StoreBaseHash TupleLoaderHashDerby -- extends --> TupleLoaderHashBase FmtLayout2IndexDerby -- extends --> FmtLayout2HashDerby StoreTriplesNodesIndexDerby -- extends --> StoreBaseIndex TupleLoaderIndexDerby -- extends --> TupleLoaderIndexBase Also look at: - JDBC.java - DatabaseType.java - StoreFactory.java - SDB.java And the existing tests. May I ask you what motivates you in adding MonetDB? I've never used it myself and, indeed, I use TDB instead of SDB. Transactions are coming, hopefully in the 0.9.0 release of TDB. Last but not least, it's not only about the code. You should be willing to support the users of your code too. Once you add support for MonetDB, people will start using it and, as they use your code, they'll find bugs and they'll ask you for more features, eventually. You should be willing to put some effort in fixing the bugs, at least... and you can always say "no" politely to new features. Until, someone else, who really needs the new feature and he/she is willing to put some effort, will take over and push the software a step further. Once you start, you might have more specific questions on SDB design. You can post your questions here or on [email protected] mailing list. The more you demonstrate you put some effort the more likely you'll receive helpful answers back from the SDB developers. If you don't put enough effort and expect others will do it for you, I am afraid, you risk to have not much back. To conclude, it you are motivated and you think you'll have fun doing it (and you need it for your work): go ahead, it's not a terribly huge task and it could be a nice contribution (in particular for all the MonetDB users out there). Paolo > > Thanks in advance! > > Best Regards > Tobias Willig >
