Databases Reference
In-Depth Information
■
the Data pump status table is created in the default permanent tablespace of the user performing the export/
import. therefore, if the user has no privileges to create a table in the default tablespace, the Data pump job will fail, with
an
ORA-31633
error.
Tip
The status table is dropped by Data Pump upon successful completion of an export or import job. If you use
the
KILL_JOB
interactive command, the master table is also dropped. If you stop a job with the
STOP_JOB
interactive
command, the table isn't removed and is used in the event you restart the job.
If your job terminates abnormally, the master table is retained. You can delete the status table if you don't plan to
restart the job.
When Data Pump runs, it uses a database directory object to determine where to write and read dump files and
log files. Usually, you specify which directory object you want Data Pump to use. If you don't specify a directory object,
a default directory is used. The default directory path is defined by a data directory object named
DATA_PUMP_DIR
.
This directory object is automatically created when the database is first created. On Linux/Unix systems this directory
object maps to the
ORACLE_HOME/rdbms/log
directory.
A Data Pump export creates an export file and a log file. The export file contains the objects being exported. The
log file contains a record of the job activities. Figure
13-1
shows the architectural components related to a Data Pump
export job.
OS command
starts DP job:
$ expdp user/pwd
dumpfile=exp.dmp
logfile=exp.log
directory=dp_dir
OS command can be
used to attach to
running DP job:
interactive
command
mode entered via
Ctrl+C
Export > status
$ expdp user/pwd
attach=<JOB_NAME>
database
master
OS process
ora_dmNN_<SID>
DP_DIR
directory object
/oradump
SYS_EXPORT_<JOB>_N
(status table)
worker
OS process(es)
ora_dwNN_<SID>
database objects
(tables, indexes,
grants, and so on)
DBMS_DATAPUMP
DBMS_METADATA
shared pool memory
OS files
/oradump
exp.dmp
/oradump
exp.log
Figure 13-1.
Data Pump export job components
