Tales From A Lazy Fat DBA

What is a Master Table & what’s the significance or importance of  it during a Data Pump Job ?

At the heart of the Data Pump operation is the Master Table.  This table is created at the beginning of a Data Pump operation and is dropped at the end of the successful completion of a Data Pump operation. The Master Table can also be dropped if the job is killed using the kill_job interactive command. If a job is stopped using the stop_job interactive command or if the job is terminated unexpectedly, the Master Table will be retained.
The Master Table is used to track the detailed progress information of a Data Pump job:

* The current set of dump files.
* The current state of every object exported or imported and their locations in the dump file set.
* The job’s user-supplied parameters.
* The status of every worker process.
* The state of current job status and restart information.

The Master Table is created in the schema of the current user running the Pump Dump export or import, and it keeps tracks of lots of detailed information.  As a result, this table can take up a significant amount of storage space.

[oracle@localhost /]$ expdp larry/champion tables=etr,orders directory=dpump

Export: Release 10.2.0.1.0 – Production on Tuesday, 01 May, 2012 23:27:46

Copyright (c) 2003, 2005, Oracle.  All rights reserved.

Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 – Production
With the Partitioning, OLAP and Data Mining options
Starting “LARRY”.”SYS_EXPORT_TABLE_01″:  larry/******** tables=etr,orders directory=dpump dumpfile=test.dmp logfile=testlog.log content=all
Estimate in progress using BLOCKS method…
Processing object type TABLE_EXPORT/TABLE/TABLE_DATA
Total estimation using BLOCKS method: 128 KB
Processing object type TABLE_EXPORT/TABLE/TABLE
Processing object type TABLE_EXPORT/TABLE/INDEX/INDEX
Processing object type TABLE_EXPORT/TABLE/INDEX/STATISTICS/INDEX_STATISTICS
Processing object type TABLE_EXPORT/TABLE/STATISTICS/TABLE_STATISTICS
. . exported “LARRY”.”ETR”                            5.648 KB       7 rows
. . exported “LARRY”.”ORDERS”                            5.734 KB       5 rows
Master table “LARRY”.”SYS_EXPORT_TABLE_01″ successfully loaded/unloaded
******************************************************************************
Dump file set for LARRY.SYS_EXPORT_TABLE_01 is:
/u01/app/oracle/oradata/test.dmp
Job “LARRY”.”SYS_EXPORT_TABLE_01″ successfully completed at 23:27:51

Example: As highlighted in Bold the Master Table is successfully loaded and unloaded at the end of the Data Pump Job. Created in the same schema (Larry) which initiated the DP job as underlined created by the name of: SYS_EXPORT_TABLE_01

Let the Red Prevail …
Prashant D