We can play around with the changeSummary we pass in the request if the record really does not exist we can not merge or update, so it would be better if you can give us an example to check the feasibility.
I am looking functionality to MultiDomain MDM.
In MDM provisioning tool, you may configure similar record component which you can add to a record view layout. When you create a record, the component displays records that are similar to record that the you create. You can review the records that appear in the component to ensure that the records you create are not duplicates. If required you can merge with the existing one else go ahead and create a new record.
Refer to below Kb article:
In MDM when we merge, we create a Cross reference record and calculate the best version for it to reflect in BO. so it may not be exactly the same concept of power center (insert or update).
Merge and update in MDM are two different things.
I believe what you're asking is "Search Before Create" functionality. This is available in E360 screens thru Similar records widget configuration as mentioned in below KB
But this functionality is limited to E360 only and not applicable for BES REST calls that fired directly. This is due to the manual intervention that's needed when multiple matches are returned for the input data.
Detailed requirement addressed for "Search before Create" below:
As a business user, I should be able to see a list of possible duplicates when I try to create a new business entity, to let me know that I might be creating a duplicate of an existing record if I go ahead and save the record, provided that the Create Business Entity Page I am working in has been configured to perform "search before creating". If it has been configured thus, the system must show me the potential duplicates within a few milliseconds from when I try to save the new record. If the record I was trying to create is in the list of potential duplicates, then I should be allowed to choose whether to continue to with the Save, or whether to open one of the records from the list so that I can edit it.
Below are key outcomes as part of this flow:
a. User reviews the duplicates and selects to proceed with create
b. User continues and merges his original changes with existing entity
c. User selects to create new entity by merging an existing one into the new one, that is doing a "copy" operation
d. User discards the original values and proceeds to the found entity to edit
e. User identifies potentially matched entity as a related entity and creates a relationship between the two
Features released in 10.1:
1. No records are found at all ... in which case the "Similar or Related Records" widget should say that. In this case the user will continue to create their new record
2. Search finds some records, but none of them are the same as what the user is adding and none of them are related to what the user is adding. In that case, following a review user ignores them.
3. Search finds one or more records that are the same as the record they are adding. The user can cancel the create process and can select one record to continue with.
Features extended in 10.3:
3b. Search finds multiple records that are the same as the record they are adding - they can select the MULTIPLE records and open them in the match/merge screen and merge them
4. Search finds one or more records that are RELATED to the record they're creating ... they can select one or more records and switch on something to indicate that those records are related to the record they're adding ... give them a way to move them into the relevant related records section in e360 and provide additional attributes for the relationship if application.
5. User needs to be able to configure search in such a way that in flow a user would need to be able to explicitly discard the potential matches found in the system before proceeding with creation of new record. He also might need to provide some specific reasons for doing this in form of preset list of values