♨️How To Use DataPump Export (EXPDP) To Export From Physical Standby….pdf

1. ♨ How To Use DataPump Export (EXPDP) To Export From Physical Standby Database.
This document describes how to successfully execute DataPump Export to export
data from a Physical Standby database.
Taking dump
fi
le from a large primary database for some reason can be a challenge for DBA.
Although existing features such as parallelism can be speed up process but this load cannot be
tolerated on the production database.
So once solution is taking dump on standby.
SOLUTION
It's important to know that Data Pump Export (expdp) cannot be executed directly on the Physical
Standby database. This is due to the fact that Data Pump Export needs to create and maintain a
Master Table which requires that a database would be open in "READ WRITE" mode. Therefore it
is necessary to connect from a "non-Standby" database (which will maintain the Master Table) to
the Physical Standby database using parameter NETWORK_LINK.
The NETWORK_LINK parameter initiates an export by using a valid database link. This means that
the system to which the expdp client is connected contacts the Physical Standby database
referenced by the source_database_link, retrieves data from it, and writes the data to a dump
fi
le
set back on the connected system.
The Physical Standby database must be opened in "READ ONLY" mode.
Steps to execute to export from Physical Standby
Database
On Physical Standby Database:
-- Connect to Physical Standby database and check its status
SQL> select instance_name, status from v$instance;
INSTANCE_NAME STATUS
---------------- ------------
<STDBY_DB_NAME> MOUNTED
-- Cancel managed recovery and open database in "READ ONLY" mode.
SQL> alter database recover managed standby database cancel;
SQL> alter database open read only;
-- Verify database status
SQL> select instance_name, status from v$instance;
INSTANCE_NAME STATUS
---------------- ------------
<STDBY_DB_NAME> OPEN
SQL> select open_mode from v$database;

2. OPEN_MODE
--------------------
READ ONLY
On "Non Standby" Database (another database as a proxy, this can be a light with minimal
resource and use only for this way.
-- create DB Link, Oracle Directory and test it
SQL> create database link expdp_primary connect to system identi
fi
ed by <password> using
‘standby_database’;
SQL> select db_unique_name from v$database;
SQL> select db_unique_name from v$database@expdp_primary;
SQL> create directory datapump as ‘/tmp’;
-- Use NETWORK_LINK to database link above to connect to the Physical Standby database:
$expdp system/<password> directory=datapump
network_link=expdp_primary full=y
dump
fi
le=standby_database.dmp
log
fi
le=standby_database.log
♨ Also another option is convert standby database to snapshot and take export pump and
fi
nally
comver to physical standby.
This can done by a manual script under a job.
*********************************
Typical Errors when exporting from Physical Standby databases
ISSUE:
UDE-01033: operation generated ORACLE error 1033
ORA-01033: ORACLE initialization or shutdown in progress
UDE-00003: all allowable logon attempts failed
CAUSE:
•No NETWORK_LINK parameter was used to connect to Physical Standby database
- AND -
•Physical Standby runs in "MOUNTED" state
SOLUTION:
•Use NETWORK_LINK={database link} to connect Physical Standby database.
•Make sure that a valid database link exists to connect to Standby database.
•Run Physical Standby database in "READ ONLY" mode.
ISSUE:
ORA-39006: internal error
ORA-39065: unexpected master process exception in DISPATCH
ORA-01033: ORACLE initialization or shutdown in progress
ORA-02063: preceding line from {database link}

3. ORA-39097: Data Pump job encountered unexpected error -1033
CAUSE:
•Physical Standby runs in "MOUNTED" state
SOLUTION:
•Connect to Physical Standby database to open the database in "READ ONLY MODE".
Some recommendations for taking dump on large databases:
- Use standby to prevent load a
ff
ected on primary database.
- Use parallelism to use more process and minimize time.
- Take dump as data_only
fi
rst
- Take all indexes as a sql
fi
le by import
- Run DDL commands from multiple sessions at the same time to index creation
- Exclude statistsics from export if possible
- For partitions table use merge option if possible
- Optimize STREAMS_POOL_SIZE param
- Set AQ_TM_PROCESSES>0 if possible
- On Rac PARALLEL_FORCE_LOCAL=TRUE
Regards,
Alireza Kamrani