Oracle 19c New Feature: Automatic Database Diagnostic Monitor (ADDM) in Pluggable Database Level

Oracle 19c has introduced new feature (capability) which is generating ADDM report from a PDB-level, this was not possible in previous releases, as ADDM was generated from a CDB (Container Level).

The following are the steps to enable ADDM in a PDB:

SQL> alter session set container=PDB1;

Session altered.


System altered.

//configure snapshot interval for AWR

SQL> EXEC dbms_workload_repository.modify_snapshot_settings(interval=>60);

PL/SQL procedure successfully completed.

// take manual snapshot





// to check snapshsot details for PDB1 database

SQL> select * from DBA_HIST_SNAPSHOT where CON_ID=3;

As HR user I will create a new table and insert dummy data:

sqlplus hr/hr_123@PDB1

CREATE  TABLE DUMMY_SEPT (sales  number(10));


    FOR v_LoopCounter IN 1..3000 LOOP

 insert into DUMMY_SEPT values (‘4000’);   






select *  from DUMMY_SEPT;

// as SYS or SYSTEM account execute the following to take manual snapshot:





Now, I will generate ADDM Report for PDB1 database:

SQL> alter session set container=PDB1;

Session altered.

SQL> @?/rdbms/admin/addmrpt.sql

Current Instance


   DB Id    DB Name      Inst Num Instance

———– ———— ——– ————

 2381533563 ORCLCDB             1 ORCLCDB

Instances in this Workload Repository schema


  DB Id      Inst Num   DB Name      Instance     Host

———— ———- ———    ———-   ——

  2381533563     1      ORCLCDB      ORCLCDB      oracle-19c-v

Using 2381533563 for database Id

Using          1 for instance number

Specify the number of days of snapshots to choose from


Entering the number of days (n) will result in the most recent

(n) days of snapshots being listed.  Pressing <return> without

specifying a number lists all completed snapshots.

Listing the last 3 days of Completed Snapshots

Instance     DB Name      Snap Id       Snap Started    Snap Level

———— ———— ———- —————— ———-

ORCLCDB      ORCLCDB              1  24 Sep 2020 12:38    1

                                  2  24 Sep 2020 14:00    1

                                  3  24 Sep 2020 14:25    1

                                  4  24 Sep 2020 14:30    1

                                  5  24 Sep 2020 14:50    1

Specify the Begin and End Snapshot Ids


Enter value for begin_snap: 4

Begin Snapshot Id specified: 4

Enter value for end_snap: 5

End   Snapshot Id specified: 5

Specify the Report Name


The default report file name is addmrpt_1_4_5.txt.  To use this name,

press <return> to continue, otherwise enter an alternative.

Enter value for report_name: ADDM_PDB1_SEPT24.txt

Using the report name ADDM_PDB1_SEPT24.txt

Running the ADDM analysis on the specified pair of snapshots …

Generating the ADDM report for this analysis …

          ADDM Report for Task ‘TASK_15’


Analysis Period


AWR snapshot range from 4 to 5.

Time period starts at 24-SEP-20 02.30.46 PM

Time period ends at 24-SEP-20 02.50.05 PM

Analysis Target


Database ‘ORCLCDB’ with DB ID 2381533563.

Database version

ADDM performed an analysis of instance ORCLCDB, numbered 1 and hosted at


ADDM detected that the system is a PDB.

Activity During the Analysis Period


Total database time was 6 seconds.

The average number of active sessions was .01.



There are no findings to report.



          Additional Information


Miscellaneous Information


There was no significant database activity to run the ADDM.

End of Report

Report written to ADDM_PDB1_SEPT24.txt

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