BI Publisher performance issues

BI Publisher performance dependent on the Data source that is selected.
1 ) XML File Data Source ( XML File)
2) XMLDoc Data Source ( Peoplecode string - XML file )
3) Rowset Data Source (XMLDoc - Peoplecode string - Xml file)
4) PSQuery Data Source (Rowset - XMLDoc - Peoplecode string - Xml file)

XML File data source has better performance and PSQuery being the least as it has more conversion steps.