OBR loader process fails with "Consider increasing ResultBufferSize" error

In OBR 10.x the following error seen in loader.log

DBD::ODBC::db DESTROY failed: [unixODBC][Vertica][VerticaDSII] (10) An error occurred during query preparation: Multiple commands cannot be active on the same connection. Consider increasing ResultBufferSize or fetching all results before initiating another command. (SQL-HY000) ;return value: 19