Alfresco doc says oracle db MUST be created with charset AL32UTF8. However, my client created a db with charset WE8MSWIN1252. Does anyone know any potential problems that may be caused by different chart?
The only potential problem I can think of is internationalisation.
that is a rather big potential problem. I don't know what types of contents your client wants to manage with Alfresco, but if the managed objects have metadata with unsupported characters, you'll quickly have an acceptance problem on your hands if users can't find their documents or can't read the metadata on the web UI.