Gathering

Yesterday I received an interesting customer question:

“Do we have to gather fixed objects stats inside a PDB as well or only in the CDB$ROOT?”

The customer told me he couldn’t find anything in the documentation. Neither could I. And I did check also the usual suspects this morning “Best Practices for Gathering Statistics” – but it does not say anything about PDBs and CDBs.

Therefore I did a short test:

• Create a PDB in my Oracle 12.1.0.2 CDB:

  SQL> create pluggable database PDB3
       admin user adm identified by adm
       file_name_convert=( '/u02/oradata/CDB1/pdbseed', '/u02/oradata/CDB1/pdb3');

• Open the PDB:

  SQL>