To fix this error, where clause requires additional single quotes – like,
When we export some tables with content=metadata_only and import, the table stats get locked by Oracle.
Post import, the stats will need to be unlocked.
explain plan for SELECT * FROM REGIONS WHERE REGION_ID =1;
SELECT * FROM TABLE(DBMS_XPLAN.DISPLAY());
SELECT * FROM REGIONS WHERE REGION_ID =1;
select * from table(dbms_xplan.display_cursor);
right click in SQL Developer & ‘Explain Plan’
SELECT task_name, status,count(1) FROM DBA_PARALLEL_EXECUTE_CHUNKS GROUP BY task_name, status order by status ;
$ lsnrctl stop
Now that the listener is stopped, log in to SQL*Plus as the SYSTEM user using the orcl service name to determine whether you can still connect to the database.
$ sqlplus system@orcl
$ lsnrctl start
$ lsnrctl status
A CDB includes the following components:
Each of these components is called a container. Therefore, the root is a container, the seed is a container, and each PDB is a container. Each container has a unique container ID and name within a CDB.
Open a terminal window, execute the oraenv command to set the environment variables and connect to the database orcl.
$ . oraenv
ORACLE_SID = [oracle] ? orcl
The Oracle base has been set to /scratch/u01/app/oracle
Check if the database is a non container database.
select name, cdb, con_id from v$database;
Issue the SQL statement that returns the port that is configured for EM Express.
select instance_name, status, con_id from v$instance;
If a port number is not returned by this statement, then you must manually configure an HTTPS port for this CDB, as described in “Configuring the HTTPs Port”.
select dbms_xdb_config.gethttpsport() from dual;
Display the PDBs
select con_id, name, open_mode from v$pdbs;
ALTER SESSION SET CONTAINER=orclpdb;
alter pluggable database orclpdb open;
SELECT dbms_xdb_config.gethttpsport() from dual;
$ lsnrctl status
SQL> show parameter dispatchers;
Oracle Enterprise manager
In your Web browser, enter the URL to access Enterprise Manager: https://hostname:portnumber/em.
Note:Starting with Oracle Database 19c, Oracle EM Express, the default management option for Oracle Database, is based on Java JET technology. Currently, only the Performance menu is available in the 19c JET version. Therefore, we are using the 18c Flash Oracle EM Express in our tutorials. Use the following command to revert to Flash Oracle EM Express:
SQL> @?/rdbms/admin/execemx emx
To return to 19c JET Oracle EM Express, use the following command:
SQL> @?/rdbms/admin/execemx omx
ALTER USER HR ACCOUNT UNLOCK IDENTIFIED BY password;
The system responds:
The HR account is unlocked and its password is password.