A few days ago my colleagues migrated a small part of a very big DB to AWS.
As one of the apps remains in on premises, they created a Dblink between the on-prem db and the AWS Oracle RDS.
Since Monday, they are having performance problems in the on prem DB, but not in any query that uses the dblink.
What is even stranger is that the top problematic SQLs have as top event SQL Net more from dblink. But none of them use a dblink.
Actually, the queries that use the Dblink are all working fine.
Anyone can give me a hint, really appreciated