For a PDB that uses shared undo, you can optionally include the AUXILIARY DESTINATION clause to specify a location for the auxiliary instance that stores data files restored as part of the Flashback Database operation. If you omit this clause, then the auxiliary instance is created in the fast recovery area.
LOCAL_UNDO_ENABLED=FALSE then is in shared undo mode
If you are using shared undo mode, then the syntax is a little different as you will have to specify a location for an auxiliary instance.
FLASHBACK PLUGGABLE DATABASE PDB1 TO RESTORE POINT R1 AUXILIARY DESTINATION '/u01/aux';
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