Backstory:
For some reason the traditional ESRI solutions for doing this have failed to move the Attachments as well, so I wanted to see if I could use FME to do this.
I have a SDE feature class with 43,000+ records and 84,000+ attachments. I have successfully used FME to write new features to an SDE Feature Class and add attachments at the time of writing. This however would be moving existing features and their attachments to a new SDE Feature Class in a different database. The thought would be to read (with the "Ignore Relationship Info" parameter disabled) the existing features, the attachment relationship table, and the attachments and then use the current origin and destination relationship ids as the values used as the temporary relationship ids when writing them as new features and attachments into the new location.
Question:
Has anyone attempted something similar? Second, the attachments are not being read. The feature and the attachment relationship table are read and contain results, but the attachments does not return any records. Thoughts?