Choose two.
Which two are true about gathering optimizer statistics?
A.Executing DBMS_STATS.GATHER_DATABASE_STATS while connected to CDB$ROOT gathers object statistics only in PDB$SEED. B.Executing DBMS_STATS.GATHER_DATABASE_STATS while connected to CDB$ROOT gathers object statistics only in CDB$ROOT. C.Executing DBMS_STATS.GATHER_DATABASE_STATS while connected to CDB$ROOT gathers object statistics in all open pluggable databases (PDBs). D.System statistics can be gathered only while the CDB is in MOUNT state. E.Executing DBMS_STATS.GATHER_DATABASE_STATS while connected to a PDB opened in read/write mode gathers object statistics for that PDB.正确答案BE
