That was my blog entry showing how you can use the Database plugin's Query Service resource to obtain metric values based on data in a database. The graph is just the normal metric graphs for any resource in RHQ - it just so happens this resource's metric comes from a database. You can use the RHQ REST interface to obtain any metric data in JSON data format - including this data you see in the graph. From there you can import the data to any data analysis tool or spreadsheet. I think if you google, you'll find information on how you can use a REST client and the RHQ REST API to obtain metric data from it (I seem to remember Heiko or someone mentioning how to do this, but do not remember where).