Exam 1z0-083 topic 1 question 22 discussion

BC test: SQL> select count(*) from sys.dba_tab_statistics where last_analyzed is not null; COUNT(*) ---------- 3610 SQL> EXEC DBMS_STATS.GATHER_DATABASE_STATS; PL/SQL procedure successfully completed. SQL> select count(*) from sys.dba_tab_statistics where last_analyzed is not null; COUNT(*) ---------- 3649 SQL> alter session set container=ORCLPDB1; Session altered. SQL> select count(*) from sys.dba_tab_statistics where last_analyzed is not null; COUNT(*) ---------- 3507 SQL> EXEC DBMS_STATS.GATHER_DATABASE_STATS; PL/SQL procedure successfully completed. SQL> select count(*) from sys.dba_tab_statistics where last_analyzed is not null; COUNT(*) ---------- 3598

BC are correct. Tested in LAB.

B y E Test in my LAB 19C SQL> select max(last_analyzed) from sys.dba_tab_statistics; MAX(LAST_ANALYZED) ------------------ 14-OCT-24 SQL> show pdbs CON_ID CON_NAME OPEN MODE RESTRICTED ---------- ------------------------------ ---------- ---------- 2 PDB$SEED READ ONLY NO 3 PDBDEV READ WRITE NO SQL> show con_name CON_NAME ------------------------------ CDB$ROOT SQL> EXEC DBMS_STATS.GATHER_DATABASE_STATS; PL/SQL procedure successfully completed. SQL> select max(last_analyzed) from sys.dba_tab_statistics; MAX(LAST_ANALYZED) ------------------ 04-NOV-24 SQL> alter session set container=PDBDEV; Session altered. SQL> select max(last_analyzed) from sys.dba_tab_statistics; MAX(LAST_ANALYZED) ------------------ 04-NOV-24 SQL>

B and C are correct.

For option C, the tricky point is the word "only. When connected to CDB$ROOT, you can also collect object statistics at PDB level if specified. For option D, all containers under the CDB share the same hardware. I can't see why it was incorrect as DBMS_STATS.GATHER_SYSTEM_STATS should be executed at CDB level and applies to the PDBs under it.

BC correct

I think BC

Suggested CE are mutuallz exclusive.

BC is correct .https://docs.oracle.com/en/database/oracle/oracle-database/21/arpls/DBMS_STATS.html#GUID-9761DFB9-8710-45D9-9ACE-A4FD37FD69F5 The application PDB user, uses this preference to determine whether to allow the application root to interact with the statics gathering in PDB. During the statistics gathering of a metadata linked table in the application root, if the statistics in a PDB are in stale state, the application root triggers the statistics gathering for the particular PDB. Using this preference, the user can either execute or ignore the command from the application root. You can set the following values: TRUE—Allows the application root trigger the statistics gathering on metadata linked table in application PDB if the statistics on PDB are stale. FALSE—Ignores the statistics gathering command triggered from application root. The default value is FALSE. Note: CDB root, different from application root, never triggers statistics gathering on the PDBs and it is not controlled by this preference.

BC = 100% correct

B,C are correct answer. Tested on my lab

B and E

B & C are correct. Tested on my system.

B is obvious, also C is true as I've just tested in practice on 19c - EXEC DBMS_STATS.GATHER_DATABASE_STATS launched on CDB$ROOT did NOT calculated stats on PDB1:EMP table I created.

SQL> show pdbs CON_ID CON_NAME OPEN MODE RESTRICTED ---------- ------------------------------ ---------- ---------- 2 PDB$SEED READ ONLY NO 3 HR READ WRITE NO SQL> alter session set container = PDB$SEED; Session altered. SQL> show con_name CON_NAME ------------------------------ PDB$SEED SQL> select count(*) from sys.dba_tab_statistics where last_analyzed is not null; COUNT(*) ---------- 2290 SQL> EXEC DBMS_STATS.GATHER_DATABASE_STATS; BEGIN DBMS_STATS.GATHER_DATABASE_STATS; END; * ERROR at line 1: ORA-20000: database or pluggable database open for read-only access ORA-06512: at "SYS.DBMS_STATS", line 42559 ORA-06512: at "SYS.DBMS_STATS", line 42521 ORA-06512: at "SYS.DBMS_STATS_INTERNAL", line 17263 ORA-06512: at "SYS.DBMS_STATS", line 42414 ORA-06512: at "SYS.DBMS_STATS", line 42549 ORA-06512: at line 1

BC: https://mikedietrichde.com/2016/10/21/gather-fixed-objects-stats-in-pdbs-as-well/

corect BC tested on 19c and 12.2 test provided by ald85 is not accurate, E is not corect try creating simple tales in ROOT and PDB than gather db stats from ROOT, and you will see that PDB tables stats will not be gathered.