Changing objects from one type to another type is pretty easy..One dql statement is all it needs..However there are a few constraints on the hierarchy with which you can change types.
Rules and Constraints on Changing Types
There are some constraints when you change an object’s type:
• The object’s current type and the new type must have the same type identifier, and they must be SysObjects or SysObject subtypes.
• The type identifier is the first two characters in an object ID. For example, all documents have 09 as their type identifier.
• The old and new types cannot be at the same level in the type hierarchy.
You can move objects up or down in the object hierarchy but not laterally. For example, the dm_document and dm_process object types are peers—they are at the same level because both are direct subtypes of dm_sysobject. Now, suppose you have two dm_document subtypes, proposal_doc and report_doc. Using CHANGE…OBJECT, you can change a proposal_doc or report_doc object to a dm_document object or a dm_document object to a proposal_doc or report_doc object, but you cannot change any of the document types or subtypes to dm_process objects.
You simply cant change r_object_type to change an object’s type. You must use the “change object” dql statement to accomplish this.
Please refer to page 59 of 5.2.5 DQL Guide:
Changing objects from one type to another type is pretty easy..One dql statement is all it needs..However there are a few constraints on the hierarchy with which you can change types.
Rules and Constraints on Changing Types
There are some constraints when you change an object’s type:
• The object’s current type and the new type must have the same type identifier, and they must be SysObjects or SysObject subtypes.
• The type identifier is the first two characters in an object ID. For example, all documents have 09 as their type identifier.
• The old and new types cannot be at the same level in the type hierarchy.
You can move objects up or down in the object hierarchy but not laterally. For example, the dm_document and dm_process object types are peers—they are at the same level because both are direct subtypes of dm_sysobject. Now, suppose you have two dm_document subtypes, proposal_doc and report_doc. Using CHANGE…OBJECT, you can change a proposal_doc or report_doc object to a dm_document object or a dm_document object to a proposal_doc or report_doc object, but you cannot change any of the document types or subtypes to dm_process objects.
Reference:
https://forums.emc.com/forums/thread.jspa?tstart=0&threadID=18561
https://forums.emc.com/forums/thread.jspa?tstart=0&threadID=18626