SAMPLE parameter in datapump

SAMPLE:

This parameter allows you to export subsets of data by specifying the percentage of data to be sampled and exported. The sample_percent indicates the probability that a block of rows will be selected as part of the sample. It does not mean that the database will retrieve exactly that amount of rows from the table.

DEMO:

C:\>expdp system/rman tables=scott1.countries dumpfile=oe.dmp sample="scott1"."countries":50

Export: Release 11.1.0.6.0 - Production on Tuesday, 11 January, 2011 10:22:07

Copyright (c) 2003, 2007, Oracle.  All rights reserved.

Connected to: Oracle Database 11g Enterprise Edition Release 11.1.0.6.0 - Produc

tion

With the Partitioning, OLAP, Data Mining and Real Application Testing options

Starting "SYSTEM"."SYS_EXPORT_TABLE_01":  system/******** tables=scott1.countrie

s dumpfile=oe.dmp sample=scott1.countries:50

Estimate in progress using BLOCKS method...

Processing object type TABLE_EXPORT/TABLE/TABLE_DATA

Total estimation using BLOCKS method: 64 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/INDEX/STATISTICS/INDEX_STATISTICS

Processing object type TABLE_EXPORT/TABLE/COMMENT

Processing object type TABLE_EXPORT/TABLE/CONSTRAINT/REF_CONSTRAINT

Processing object type TABLE_EXPORT/TABLE/STATISTICS/TABLE_STATISTICS

. . exported "SCOTT1"."COUNTRIES"                        6.031 KB      11 rows

Master table "SYSTEM"."SYS_EXPORT_TABLE_01" successfully loaded/unloaded

******************************************************************************

Dump file set for SYSTEM.SYS_EXPORT_TABLE_01 is:

  D:\ORACLE\ADMIN\RMAN\DPDUMP\OE.DMP

Job "SYSTEM"."SYS_EXPORT_TABLE_01" successfully completed at 10:23:23

C:\>expdp system/rman tables=scott1.countries dumpfile=oop.dmp sample="scott1"."countries":50

Export: Release 11.1.0.6.0 - Production on Tuesday, 11 January, 2011 10:23:47

Copyright (c) 2003, 2007, Oracle.  All rights reserved.

Connected to: Oracle Database 11g Enterprise Edition Release 11.1.0.6.0 - ProductionWith the Partitioning, OLAP, Data Mining and Real Application Testing options

Starting "SYSTEM"."SYS_EXPORT_TABLE_01":  system/******** tables=scott1.countrie

s dumpfile=oop.dmp sample=scott1.countries:50

Estimate in progress using BLOCKS method...

Processing object type TABLE_EXPORT/TABLE/TABLE_DATA

Total estimation using BLOCKS method: 64 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/INDEX/STATISTICS/INDEX_STATISTICS

Processing object type TABLE_EXPORT/TABLE/COMMENT

Processing object type TABLE_EXPORT/TABLE/CONSTRAINT/REF_CONSTRAINT

Processing object type TABLE_EXPORT/TABLE/STATISTICS/TABLE_STATISTICS

. . exported "SCOTT1"."COUNTRIES"                        6.078 KB      14 rows

Master table "SYSTEM"."SYS_EXPORT_TABLE_01" successfully loaded/unloaded

******************************************************************************

Dump file set for SYSTEM.SYS_EXPORT_TABLE_01 is:

  D:\ORACLE\ADMIN\RMAN\DPDUMP\OOP.DMP

Job "SYSTEM"."SYS_EXPORT_TABLE_01" successfully completed at 10:25:01

C:\>expdp system/rman tables=scott1.countries dumpfile=lop.dmp sample="scott1"."countries":50

Export: Release 11.1.0.6.0 - Production on Tuesday, 11 January, 2011 10:25:12

Copyright (c) 2003, 2007, Oracle.  All rights reserved.

Connected to: Oracle Database 11g Enterprise Edition Release 11.1.0.6.0 - Production With the Partitioning, OLAP, Data Mining and Real Application Testing options

Starting "SYSTEM"."SYS_EXPORT_TABLE_01":  system/******** tables=scott1.countrie

s dumpfile=lop.dmp sample=scott1.countries:50

Estimate in progress using BLOCKS method...

Processing object type TABLE_EXPORT/TABLE/TABLE_DATA

Total estimation using BLOCKS method: 64 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/INDEX/STATISTICS/INDEX_STATISTICS

Processing object type TABLE_EXPORT/TABLE/COMMENT

Processing object type TABLE_EXPORT/TABLE/CONSTRAINT/REF_CONSTRAINT

Processing object type TABLE_EXPORT/TABLE/STATISTICS/TABLE_STATISTICS

. . exported "SCOTT1"."COUNTRIES"                        6.054 KB      13 rows

Master table "SYSTEM"."SYS_EXPORT_TABLE_01" successfully loaded/unloaded

******************************************************************************

Dump file set for SYSTEM.SYS_EXPORT_TABLE_01 is:

  D:\ORACLE\ADMIN\RMAN\DPDUMP\LOP.DMP

Job "SYSTEM"."SYS_EXPORT_TABLE_01" successfully completed at 10:26:31

Note:Everytime you perform the export count of rows would be different as it take out the sample of subset of a table.

Enjoy:-)