When configuring the jdbc data source, on the conection pooling tab, one of the options is for the MaxOpenPreparedStatements. I currently have it set to a value of 20. My pentaho server is still just being used for internal testing. If I go and run a single report, it fails with the error:

"SQL-query did not execute successfully. MaxOpenPreparedStatements limit reached"

What is a recommended/best practice for the number of MaxOpenPreparedStatements to configure? Is it based on the number of reports? Or the number of users? (i.e. - if I expect to have 10 reports and 100 users, do I need MaxOpenPreparedStatements set to 100? Why is 20 insufficient for a single user to run a single report? The report does have dropdown/parameters which have to issue queries. The report developer says that there are 13 different queries used by the report.)

Note - I saw that the documentation permits entering 0 for an unlimited number of MaxOpenPreparedStatements, but our IT department said that is not allowed and we need to pick an actual number. They initially picked 10 and we convinced them to increase it to 20, but the error still occurs.