Why are values being deleted rather than added when I perform a partial override when the survivorship rule is aggregation?

Question

Entity updates have been posted to Reltio with the partial override, a few of the records got overwritten(old values were deleted) with the latest attribute values through their attribute survivorship rule is aggregation.

This behavior results when we don't set the partial override. But we checked all API request calls sent with partial override.

Now we did not understand why records have been overwritten? This is happening only for few records and it's not consistent.

Answer

• By default partial override of a Nested attribute works as a full override.  We remove all existing values of a Nested attribute from the object slice using the incoming crosswalks.  The is followed by inserting the new incoming values. 
  
  If a customer wants to override Nested attributes partially, we enable partial override of a Nested attributes feature.   This is a definition in the physical tenant storage (refer to  https://docs.reltio.com/entitiesapi/enablenestedpartialoverrideoption.html). 
  

   "enableNestedPartialOverride": true,

• This setting will retain the existing nested attributes along with adding the new nested attribute information.  It retains the existing sub-nested attributes along with adding the new sub-nested attribute information because the system should have the ability to update existing sub-nested attribute information instead of appending the new info alongside.
• The expected behavior is that without keyAttributeURIs, we should add new values without deleting existing values. 

Example:

"keyAttributeURIs": [
"configuration/entityTypes/Individual/attributes/Identifiers/attributes/Type",
"configuration/entityTypes/Individual/attributes/Identifiers/attributes/ID"
],

• When you enable partial override for nested attributes and you send simultaneous requests, we recommend specifying the isRetryOperationOnConflict optional parameter.   This can be applied using

POST https://<environment>.reltio.com/reltio/tenants/LNFTY/<tenantID>/optionalParameters