I'm hoping for some advice on the best procedure for appending related feature layers in a AGOL feature service.
We have a hosted feature service on AGOL updating from a Survey123 form. It includes a Survey point feature layer and several repeats, 4 of which are point feature layers with potential attachments and related to that parent Survey layer (through parentGlobalID). There is also a table, again with repeats related to the Survey point. This feature service is currently live.
There are two older iterations of the feature service, each with the same basic structure of the Survey layer and the several repeats layers with attachments. The parent Survey feature layers in these have slightly different schemas from the current one, with a small number of fields having being added/removed/renamed in the iterations. These feature services are no longer live.
We wish to append the two older feature services to the current feature service, maintaining the relationships for each repeat and attachments to the parent survey. Bearing in mind the Append tool only allows one target dataset at a time, and therefore feature service-to-feature service is not possible, what is the best procedure to carry this out? If I append the Survey layers first, will the repeats then relate as expected?
I tried to test this with local file geodatabase copies but found that ticking "Preserve Global IDs" in the Append tool resulted in a 999999 error. With this unticked the append did work, but surely that would result in the relationships being broken as the GlobalID-parentGlobalID relationships need to be maintained? I'm wary of testing it on the current live layer.
Thanks for any help.