Hi, We use MonetDB v4.26.4 (Nov 2008-sp2) for our application with the XQuery frontend. Often, queries are executed very fast, but sometimes, execution of the same query takes significantly more time. For example: We insert a XML document of 1.4Mb. with a maximum depth of 4. The document is structured as follows: <rootelement> <item> <child1> <sha1>sha1-value</sha1> <md5>md5-value</md5> </child1> </item> ... </rootelement> We have 8k 'item' elements. Often the insertion of this document is performed in ~0.5s, which is fine. But when the system is performing IO (e.g. copying a large file), the insertion can take up to 6 minutes. So I have two questions: 1) What is the cause of this large difference in execution times; 2) Is there a way to configure MonetDB (or the server) in such a way that the difference between the 'fast' and 'slow' is smaller. Regards, John van Schie