After I create and configure a new data base driver under preferences, this new driver is not shown among the ones available in the configuration of DB nodes.
I'm using the community edition. Is this a restriction of this version?
Or, what should I do to have them showing up?
I restarted knime after creating the new driver (although I didn't expect that to be necessary), but still can't see it in the configuration for the node.
in contrast to other tools KNIME has no restriction on the supported JDBC drivers. So it might be a problem with the driver file. Can you have a look in the KNIME log file to see if an error occurs when KNIME trys to register the driver. To view the log file open KNIME and go to View->Open KNIME Log. In the log file search for "DatabaseDriverLoader". This is the component that is responsible for loading the JDBC drivers.
It would be also good to know which driver you want to register. For example some JDBC driver require some companion files that need to placed in the jre/lib/ext directory of your KNIME installation.