ATP AWR Generation

Kindly assist in clarifying below doubts , I have tried exploring at so many blogs but couldn't understand it ,

1. In a multitenant database , CBD/PDB will have a different dbid ? I see we have dbid,con_dbid , are these 2 different ?
2. We created a new ATP instance today and I am trying to generate AWR/ASH reports from sql developer , two issues here - 1. I was expecting to see the snapshots starting from today only since we created ATP instance today but I could see old days snapshots as well , how is that possible?

Second issue is , when I am trying to generate AWR/ASH from sqldeveloper via DBA view pane , it gets failed with error message that couldn't find this snap id for a db id xxxx , where this dbid is different from what I see in v$database.

How can we generate cdb/pdb level AWR reports, if we would have been on physical server it simply asks for that option but how can we do it ATP when we have only sqldeveloper to access the database

Have been trying hard to understand if I am missing something , appreciate any help /reference doc that throws more insight into managing ATP instance.

Thanks,
Arpit

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