Speed up Data Pump Import by suppressing redo generation

Customer Request : Import 20GB  Dump file without downtime(Without changing into noarchivelog mode).

Problem: Database running in Archive log mode  and my archive destination size is very limited.

Solution:

Using  transform=disable_archive_logging:Y we can avoid redo generation and it will speedup import.


Test:


 Without Feature:
 ============
 Before Import:

 SQL> select * from v$recovery_area_usage where FILE_TYPE='ARCHIVED LOG';

FILE_TYPE               PERCENT_SPACE_USED PERCENT_SPACE_RECLAIMABLE NUMBER_OF_FILES     CON_ID
----------------------- ------------------ ------------------------- --------------- ----------
ARCHIVED LOG                          1.74                         0               7          0

After Import:
 SQL> set linesize 400
SQL> select * from v$recovery_area_usage where FILE_TYPE='ARCHIVED LOG';

FILE_TYPE               PERCENT_SPACE_USED PERCENT_SPACE_RECLAIMABLE NUMBER_OF_FILES     CON_ID
----------------------- ------------------ ------------------------- --------------- ----------
ARCHIVED LOG                          2.77                         0              11          0

Import elapsed 0 00:00:26

SQL> drop table test.test_table;

Table dropped.

With Feature:
==========
impdp system/manager dumpfile=test_dir:test.dmp logfile=test_dir:test_imp.log  metrics=y transform=disable_archive_logging:Y

SQL> set linesize 400
SQL> select * from v$recovery_area_usage where FILE_TYPE='ARCHIVED LOG';

FILE_TYPE               PERCENT_SPACE_USED PERCENT_SPACE_RECLAIMABLE NUMBER_OF_FILES     CON_ID
----------------------- ------------------ ------------------------- --------------- ----------
ARCHIVED LOG                          2.77                         0              11          0

Import elapsed 0 00:00:03

SQL> conn test/test
Connected.
SQL> select logging from user_tables where table_name='TEST_TABLE';

LOG
---
YES