{2 マルチテナント}PDBを削除

https://docs.oracle.com/cd/F19136_01/multi/removing-a-pdb.html#GUID-AE0FC673-3D8C-417E-B671-B2CE465E8DC3

select * from V$PDBS;
select * from cdb_pdbs;
show pdbs

drop pluggable database pdb22 INCLUDING DATAFILES;