Using New Oracle Database 12c Feature for DataPump DISABLE_ARCHIVE_LOGGING
New DataPump feature disables redo logging when loading data into tables and when creating indexes.
For my testing of the new feature I will be importing the SOE schema from the SwingBench tool. The SOE schema is about 2G and size.
Test 1
I will be to import the normal way.
$impdp parfile=impdp.par
impdp.par
directory=DATA_PUMP_DIR2
dumpfile=exp_schema_soe%U.dmp
logfile=imp_schema_soe.log
parallel=2
Before the import there were zero archive logs
In the first test we should see redolog and archive logs being generated during the import of the SOE schema.
Import
During the import we can see redologs and archivelogs are being generated during the import
After the import 25 archive logs were generated
The import had an elapsed time of 14 minutes with 41 seconds
Test 2
I will import using the new feature DISABLE_ARCHIVE_LOGGING
SQL> drop user SOE cascade;
$impdp parfile=impdp_noarchive.par
impdp_noarchive.par
directory=DATA_PUMP_DIR2
dumpfile=exp_schema_soe%U.dmp
logfile=imp_schema_soe.log
parallel=2
transform=disable_archive_logging:Y
Before the import there were zero archive logs
Import
During the import we see that there is no archivelog being generate since there is no redo generation.
After import was complete we can see that no new archivelog where generated.
The import had an elapsed time of 10 minutes with 06 seconds
Note from Oracle Documentation:
With redo logging disabled, the disk space required for redo logs during an Oracle Data Pump import will be smaller. However, to ensure recovery from media failure, the DBA should do an RMAN backup after the import completes.
Even with this parameter specified, there is still redo logging for other operations of Oracle Data Pump. This includes all CREATE and ALTER statements, except CREATE INDEX, and all operations against the master table used by Oracle Data Pump during the import.
This feature reduces the required maintenance of redo logs by DBAs
New DataPump feature disables redo logging when loading data into tables and when creating indexes.
For my testing of the new feature I will be importing the SOE schema from the SwingBench tool. The SOE schema is about 2G and size.
Test 1
I will be to import the normal way.
$impdp parfile=impdp.par
impdp.par
directory=DATA_PUMP_DIR2
dumpfile=exp_schema_soe%U.dmp
logfile=imp_schema_soe.log
parallel=2
Before the import there were zero archive logs
In the first test we should see redolog and archive logs being generated during the import of the SOE schema.
Import
During the import we can see redologs and archivelogs are being generated during the import
After the import 25 archive logs were generated
The import had an elapsed time of 14 minutes with 41 seconds
Test 2
I will import using the new feature DISABLE_ARCHIVE_LOGGING
SQL> drop user SOE cascade;
$impdp parfile=impdp_noarchive.par
impdp_noarchive.par
directory=DATA_PUMP_DIR2
dumpfile=exp_schema_soe%U.dmp
logfile=imp_schema_soe.log
parallel=2
transform=disable_archive_logging:Y
Before the import there were zero archive logs
Import
During the import we see that there is no archivelog being generate since there is no redo generation.
After import was complete we can see that no new archivelog where generated.
The import had an elapsed time of 10 minutes with 06 seconds
Note from Oracle Documentation:
With redo logging disabled, the disk space required for redo logs during an Oracle Data Pump import will be smaller. However, to ensure recovery from media failure, the DBA should do an RMAN backup after the import completes.
Even with this parameter specified, there is still redo logging for other operations of Oracle Data Pump. This includes all CREATE and ALTER statements, except CREATE INDEX, and all operations against the master table used by Oracle Data Pump during the import.
This feature reduces the required maintenance of redo logs by DBAs
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