Global Object uniqueness - How unique are object IDs?

[madsem]

Hi there,

I'm trying to figure out how unique ID's for objects returned by the API are.
Our application mirrors the account structure of our customers, we're trying to create relationships using standard FK's, but were thinking that it would save a LOT of queries if we could use Microsoft's ID's as foreign keys...

Now for Google Ads there is documentation noting how unique objects are:
https://developers.google.com/adwords/api/docs/guides/objects-methods#object_id_uniqueness

But I'm kinda missing the same from you guys :)
There is a mention of "unique" when looking at the Campaign object, but not really explained how unique...

So, how unique are especially: Account ID, Campaign ID, AdGroup ID and AdGroupCriterion ID on a global scale across all Microsoft Ads accounts?

Thank you!