Which two statements about multitenant architecture are true? 

Answer options:

A. Multiple PDBs on a single server need multiple database instances and multiple sets of database files.
B. Although consolidated into a single physical database, PDBs mimic the behavior of non-CDBs.
C. A PDB administrator can use Oracle Flashback or point-in-time recovery to retrieve lost data from a PDB, only by shutting down all the PDBs from the CDB.D. It is easier to collect performance metrics for many databases in a CDB than individual non-CDB databases.
E. It takes more time to apply a patch to one CDB that holds hundreds of PDBs than to hundreds of non-CDB databases.

BD

B: A PDB is a portable collection of schemas, schema objects, and nonschema objects that appears to an Oracle Net client as a non-CDB. All Oracle databases before Oracle Database 12c were non-CDBs. D: Ease of performance tuning - It is easier to collect performance metrics for a single database than for multiple databases. It is easier to size one SGA than 100 SGAs. References: