ObdalibPluginTroubleshooting - ConstantB/ontop-spatial GitHub Wiki
- See Sesame Workbench FAQ
- Find useful information about troubleshooting the Sesame Workbench here.
If you have issues, it is recommended to start Protege so that it displays the system's console. Every alpha and beta version of Quest will print useful debugging messages that will help you debug your problem. Moreover, in order to provide support for debugging we will require that you send us a copy of the debug messages printed in this screen.
To make Protege display a console you should start it using the scripts run.sh or run.bat. In Windows, simply click on the run.bat file located in your Protege folder. If you are in linux or mac open a terminal, cd it Protege's main folder and execute the run.sh script. For example:
cd /Applications/Protege_4.1 sh run.sh
This error may appear if the Java virtual machine's version is other different than 1.6. To verify the version used by Protege open the log printed by Protege when started using the run.bat or run.sh scripts. In the start of the printout you should see a message like the following:
Starting Protege 4 OWL Editor (Version 4.1.0, Build = 239)
Platform:
Java: JVM 1.6.0_31-b04-415-10M3646 Memory: 2138M
Language: en, Country: US
Framework: Apache Software Foundation (1.5)
OS: macos (10.6.8)
Processor: x86-64
If the JVM version is not 1.6, you should configure your system's path to use by default Java 1.6. You may also modify the run.bat or run.sh scripts to use the correct java version instead of the system's default.
If the JDBC Plugin tab is not showing up in your configuration dialog, there might be problems with class resolution and a corrupted configuration. To fix this, reset Protege's configuration. This can be done in the splash screen under the More actions menu.
MySQL doesn't support cursor based results by default. This means that every time you execute a query, MySQL sends you ALL the results of your query. When the results are big, you might run out of memory because of this. To avoid this, you should tell MySQL to use cursors at server side, and define an appropiate "fetch size", i.e., the number of rows to return each time you scroll through the result set. To do this, use the useCursorFectch=true and defaultFetchSize=N properties in your connection URL. For example:
jdbc:mysql://192.168.174.1/mydb?useCursorFetch=true&defaultFetchSize=150
Note, when using server side cursors, MySQL will first create a temporary table where all the results will be stored, then it will send the first N results. This means that using server side cursors might also slow down query answering.
More information about MySQL server side cursors can be found here.
In Windows 7 and Windows Vista it is necessary to start protege in Administrator mode otherwise sometimes you won't be able to save OBDA files. To do this, right click on the start script and do start with administrator privileges
If you experience the following error message: "Error in identifying column name", it may be due to casing problems with the SQL identifiers used in your mappings. See this dedicated page.