During peak business hours, It is not advised to export data from production .(as it might impact the performance).
So if we have a physical standby database, we can export data using datapump from standby database.
PRE-REQUISITES:
1. Physical standby database should be in READ-ONLY MODE (ACTIVE DATAGUARD)
2.We cannot run expdp directly on physical standby database. Because datapump job can be created only on a read-write database(OPEN).
So to achieve this, we will use the NETWORK_LINK parameter and run the expdp job from any non-standby database(OPEN database)
Refer open physical standby database in read only mode
STEPS:
1. Check whether standby database is in read only mode:
SQL> select database_name,DATABASE_ROLE,open_mode from v$database;
DATABASE_NAME DATABASE_ROLE OPEN_MODE
-------------- ---------------- --------------------
SALPROD PHYSICAL STANDBY READ ONLY WITH APPLY
2. create a database link on non standby database.[POINTING TO STANDBY DB]
SQL> create public database link LINK_EXPDP connect to BSSDBA identified by BSSDBA442 using 'SALdbr';
Database link created.
SQL> select sysdate from dual@LINK_EXPDP;
SYSDATE
---------
30-JAN-18
3. Create db directory on non-standby server:
create directory ERIC_DUMP as '/dumparea/dump/ERIC_DUMP'
4. Run expdp from non-standby database server:
expdp directory=ERIC_DUMP network_link=LINK_EXPDP dumpfile=standby_schema.dmp logfile=standby_schema.log tables=EMP_USER.CHANNEL_NUMBER
Export: Release 12.1.0.2.0 - Production on Tue Jan 30 10:38:59 2018
Copyright (c) 1982, 2014, Oracle and/or its affiliates. All rights reserved.
Username: / as sysdba
Connected to: Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production
With the Partitioning, Automatic Storage Management, OLAP, Advanced Analytics
and Real Application Testing options
FLASHBACK automatically enabled to preserve database integrity.
Starting "SYS"."SYS_EXPORT_TABLE_01": /******** AS SYSDBA directory=ERIC_DUMP network_link=LINK_EXPDP dumpfile=standby_schema.dmp logfile=standby_schema.log tables=EMP_USER.CHANNEL_NUMBER
Estimate in progress using BLOCKS method...
Processing object type TABLE_EXPORT/TABLE/TABLE_DATA
Total estimation using BLOCKS method: 320 KB
Processing object type TABLE_EXPORT/TABLE/TABLE
Processing object type TABLE_EXPORT/TABLE/GRANT/OWNER_GRANT/OBJECT_GRANT
Processing object type TABLE_EXPORT/TABLE/STATISTICS/TABLE_STATISTICS
Processing object type TABLE_EXPORT/TABLE/STATISTICS/MARKER
. . exported "EMP_USER"."CHANNEL_NUMBER" 171.2 KB 20000 rows
Master table "SYS"."SYS_EXPORT_TABLE_01" successfully loaded/unloaded
******************************************************************************
Dump file set for SYS.SYS_EXPORT_TABLE_01 is:
/dumparea/dump/ERIC_DUMP/standby_schema.dmp
Job "SYS"."SYS_EXPORT_TABLE_01" successfully completed at Tue Jan 30 10:47:54 2018 elapsed 0 00:07:14
We have successfully generated the export dump from standby database.
datapumpEXPDP DATAGUARD