Database Reference
In-Depth Information
We can import the resulting dumpfile using Data Pump import, as shown here:
impdp 'sys/robert@mypdb as sysdba' directory=ROBERT schemas=scott
dumpfile=test.dmp table_exists_action=truncate
As you can see, Data Pump supports CDB databases and the PDBs within the CDBs
quite nicely.
The Data Recovery Advisor
The Data Recovery Advisor is a feature in Oracle Database 12
c
that is designed to help you
find solutions when a database needs to be restored. The Data Recovery Advisor works with
both Multitennant Oracle databases and Oracle databases that are not Multitennant. Let's
look at how the Data Recovery Advisor works.
Using the Data Recovery Advisor
When you start a database, you hope that it will just do its thing and magically open.
Oracle databases do that so often that the need to restore and recover from a backup is
pretty rare. As a result, many new DBAs are not that practiced at restore and recovery.
The Data Recovery Advisor can help the new DBA to figure out what the problem is, and
what the solution is, when a database fails to start up.
For example, assume we have a multitenant database (this could also just be a regular
database and if it were, nothing would be different) called
mycdb
. When we try to start up
the database, we get the following error:
SQL> startup
ORACLE instance started.
Total System Global Area 2555445248 bytes
Fixed Size 2405904 bytes
Variable Size 671091184 bytes
Database Buffers 1862270976 bytes
Redo Buffers 19677184 bytes
Database mounted.
ORA-01157: cannot identify/lock data file 12 - see DBWR trace file
ORA-01110: data file 12:
'C:\APP\ORACLE\ORADATA\MYCDB\7FB9FCBC34324645B4750F9C5FC71A24\DATAFILE\O1_MF_
USERS_9KKGRXH1_.DBF'
It appears that the database won't open because we have a problem with a missing data
file. If you were a very junior DBA, you might not know exactly what to do in this case.
You can use the Data Recovery Advisor to provide the answers that you need.
The Data Recovery Advisor runs from RMAN or from Oracle Enterprise Manager. For
the purposes of this topic, we will use the RMAN interface to the Data Recovery Advisor.
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