ORA-31485: invalid database link
Cause: The database link used to connect from a staging database to a source database was invalid. The database link may not exist, may not be accessible to the current user, or may have been redefined since the Distributed HotLog change source was originally created
Action: Make sure that there is a database link to the source_database for the Distributed HotLog change source. Make sure this database link is accessible to the current user
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