<docbook><section><title>DBpediaPerformanceIssue</title><para> </para><bridgehead class="http://www.w3.org/1999/xhtml:h2">Poor Performance </bridgehead>
<para> </para><bridgehead class="http://www.w3.org/1999/xhtml:h3">DBpedia Load is Slow</bridgehead>
<para>Use the following instructions to troubleshoot performance issues associated with DBpedia loads --</para><para>1.
 Ensure that you have set NumberOfBuffers and MaxDirtyBuffers in the ini file as described <ulink url="Here">here</ulink>.</para><para>2.
 Ensure that you have set the default transaction isolation mode in [Parameters]  - &quot;DefaultIsolation </para><para> 2&quot; (Read Committed)</para><para>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.</para><para>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&#39;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 &#39;top&#39; to see the CPU usage stats while loading.
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