miércoles, 14 de abril de 2010

Examples of Using Data Pump Export

Example 2-1 Performing a Table-Mode Export

expdp hr/hr TABLES=employees,jobs DUMPFILE=dpump_dir1:table.dmp NOLOGFILE=y

Because user hr is exporting tables in his own schema, it is not necessary to specify the schema name for the tables. The NOLOGFILE=y parameter indicates that an Export log file of the operation will not be generated.

Data-Only Unload of Selected Tables and Rows

Example 2-2 shows the contents of a parameter file (exp.par) that you could use to perform a data-only unload of all tables in the human resources (hr) schema except for the tables countries and regions. Rows in the employees table are unloaded that have a department_id other than 50. The rows are ordered by employee_id.

Example 2-2 Data-Only Unload of Selected Tables and Rows

QUERY=employees:"WHERE department_id !=50 ORDER BY employee_id"

You can issue the following command to execute the exp.par parameter file:

> expdp hr/hr PARFILE=exp.par

Estimating Disk Space Needed in a Table-Mode Export
Example 2-3 shows the use of the ESTIMATE_ONLY parameter to estimate the space that would be consumed in a table-mode export, without actually performing the export operation. Issue the following command to use the BLOCKS method to estimate the number of bytes required to export the data in the following three tables located in the human resource (hr) schema: employees, departments, and locations.

Example 2-3 Estimating Disk Space Needed in a Table-Mode Export

> expdp hr/hr DIRECTORY=dpump_dir1 ESTIMATE_ONLY=y TABLES=employees,
departments, locations LOGFILE=estimate.log

The estimate is printed in the log file and displayed on the client's standard output device. The estimate is for table row data only; it does not include metadata.

Performing a Schema-Mode Export
Example 2-4 shows a schema-mode export of the hr schema. In a schema-mode export, only objects belonging to the corresponding schemas are unloaded. Because schema mode is the default mode, it is not necessary to specify the SCHEMAS parameter on the command line, unless you are specifying more than one schema or a schema other than your own.

Example 2-4 Performing a Schema Mode Export

> expdp hr/hr DUMPFILE=dpump_dir1:expschema.dmp LOGFILE=dpump_dir1:expschema.log
Performing a Parallel Full Database Export
Example 2-5 shows a full database Export that will have 3 parallel worker processes.

Example 2-5 Parallel Full Export

> expdp hr/hr FULL=y DUMPFILE=dpump_dir1:full1%U.dmp, dpump_dir2:full2%U.dmp
FILESIZE=2G PARALLEL=3 LOGFILE=dpump_dir1:expfull.log JOB_NAME=expfull

Because this is a full database export, all data and metadata in the database will be exported. Dump files full101.dmp, full201.dmp, full102.dmp, and so on will be created in a round-robin fashion in the directories pointed to by the dpump_dir1 and dpump_dir2 directory objects. For best performance, these should be on separate I/O channels. Each file will be up to 2 gigabytes in size, as necessary. Initially, up to three files will be created. More files will be created, if needed. The job and master table will have a name of expfull. The log file will be written to expfull.log in the dpump_dir1 directory.