Poor Performance

DBpedia Load is Slow

Use the following instructions to troubleshoot performance issues associated with DBpedia loads --

1. Ensure that you have set NumberOfBuffers and MaxDirtyBuffers in the ini file as described here.

2. Ensure that you have set the default transaction isolation mode in [Parameters] - "DefaultIsolation

2" (Read Committed)

3. If you have the hardware set up so that you have more physical disk devices on separate buses, you may benefit from additional I/O parallelization by setting Virtuoso to use striped DB - i.e. store the DB in slices on different physical devices.

4 Pay close attention to various system load indicators to see if the process is I/O or CPU bound in order to see if excessive I/O, due to swapping or the process running out of memory is causing this - when the process has enough RAM and the system's I/O devices and read buffering are healthy, the virtuoso-t process should hit and sustain
close to 100% usage on both cores during most of the load. Use 'top' to see the CPU usage stats while loading.