Need Help to Migrate Attachment Data from u_apm_case in Instance A to u_ot_case in Instance B

[Rajesh B V]

Migrate data from u_apm_case (Instance A) to u_ot_case (Instance B). Also migrate associated attachments for each record.
Note: Since these are different tables in different instances, the sys_id values of records will be different, and default sys_attachment relationships won’t work as-is.
I need help on the recommended or supported approach to migrate the attachments when:
• Source table and target table names differ (u_apm_case → u_ot_case)
• Source and target sys_ids of records differ

Note : This is one time activity which we will be performing

[GlideFather]

Hi @Rajesh B V,
are the tables of the same parent, do they share the fields? Is it more like moving incidents from instance A to instance B or more like moving problems from inst A to requests in inst B?

First thing to consider:

• Ensure that all the fields from u_apm_case exist in u_ot_case, otherwise not all data will be transferred, eventually create a mapping of how the data shall be migrated.
  
  Then the attachments: all the attachments are stored in the sys_attachment table, there you can do the transfer from the source record to the target record.
  
  If you will migrate it for example via XML, the sys ID will remain the same and thus the attachments shall be associated also.
  
  Things not to underestimate:
• How many records do you plan to migrate? Is it hundreds, thousands, millions?
• Will this be one-time transfer or regular synchronisation/integration?