There are many ways to migrate a database from A server to B server like Datapump, RMAN,etc. Using the combination of datapump and GoldenGate to migrate your database on cross-platform will minimize your down-time to even three minutes.
This method can be used for any size database from MB to TB level. Here is a simple sample to demonstrate this idea.
The prerequisites I assume that the GoldenGate has been configured in the source database and target database. To simulate the OLTP database, in my source database “SOURCE” there is a job will keep inserting a record into the table HOWIE.TEST as shown below.
CREATE PROCEDURE howie.insert_test
IS
BEGIN
insert into test values(test_seq.nextval,sysdate);
commit;
END;
/
SQL> SELECT * FROM HOWIE.TEST ORDER BY ID;
ID MOD_DATE
---------- -------------------
1 12/13/2014 21:19:17
2 12/13/2014 21:24:03
3 12/13/2014 21:31:11
.....................
21 12/15/2014 19:14:25
22 12/15/2014 19:15:25
23 12/15/2014 19:16:25
23 rows selected.
2nd step, you need to start capture process on the source database and stop replicate process on the target database
SOURCE:
GGSCI (11gGG1) 4> info all
Program Status Group Lag at Chkpt Time Since Chkpt
MANAGER RUNNING
EXTRACT RUNNING EXT1 44:56:46 00:00:01
TARGET:
GGSCI (11gGG2) 6> info all
Program Status Group Lag at Chkpt Time Since Chkpt
MANAGER STOPPED
REPLICAT STOPPED REP1 00:00:00 00:00:53
3rd step, export the source database using datapump with flashback_scn
SQL> select current_scn from v$database;
CURRENT_SCN
-----------
284867
[ggadmin@11gGG1 11.2.0]$ expdp directory=DATA_PUMP_DIR dumpfile=source.dmp logfile=source.log schemas=HOWIE flashback_scn=284867
4th step, transferred the dumpfile to the target server
[ggadmin@11gGG1 11.2.0]$ scp /u01/app/oracle/admin/SOURCE/dpdump/source.dmp 11gGG2:/u01/app/oracle/admin/TARGET/dpdump/
5th step, import the dumpfile into the target database.
[ggadmin@11gGG2 11.2.0]$ impdp directory=DATA_PUMP_DIR dumpfile=source.dmp logfile=source.log schemas=HOWIE
6th step, verify the data in the target database
SQL> SELECT * FROM HOWIE.TEST ORDER BY ID;
ID MOD_DATE
---------- -------------------
1 12/13/2014 21:19:17
2 12/13/2014 21:24:03
3 12/13/2014 21:31:11
...............
21 12/15/2014 19:14:25
22 12/15/2014 19:15:25
23 12/15/2014 19:16:25
23 rows selected.
7th step, start replicate process on the target database using ATCSN
GGSCI (11gGG2) 8> start rep rep1 atcsn 284867
Sending START request to MANAGER ...
8th step, confirm the data has been synced
SQL> SELECT * FROM HOWIE.TEST ORDER BY ID;
ID MOD_DATE
---------- -------------------
1 12/13/2014 21:19:17
2 12/13/2014 21:24:03
3 12/13/2014 21:31:11
4 12/13/2014 21:44:33
5 12/13/2014 21:45:33
6 12/13/2014 21:46:33
7 12/13/2014 21:47:33
...............
60 12/15/2014 19:53:33
61 12/15/2014 19:54:33
62 12/15/2014 19:55:33
63 12/15/2014 19:56:33
63 rows selected.
Action plan Summary
| Step |
Source
|
Target
|
| |
Source DB (11g)
|
Target DB (11g)
|
| 1 |
Configure goldengate for capture processes. |
Configure goldengate for Replicate processes. |
| 2 |
Start capture processes. |
Don’t start replicate now. |
| 3 |
start export from the source database (Mark SCN when export started.) |
|
| 4 |
Export completed. start SCP of dumpfile to target server. |
|
| 5 |
SCP completed. |
Start Import on Target database using dumpfiles. |
| 6 |
|
Import Finished. |
| 7 |
|
Start replicat using atcsn |
| 8 |
|
Replicate applied all changes |
| 9 |
when lag is zero for capture,stop capture |
wait till replicate apply all changes , lag should be zero for replicate. After this stop replicate. |
| 10 |
Redirect db connection point to target db. |
Redirect db connection point to target db. |
Data migration services
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