Default: There is no default
Allows you to specify a percentage of the data rows to be sampled and unloaded from the source database.
Syntax and Description
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 row 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. The value you supply for
sample_percent can be anywhere from .000001 up to, but not including, 100.
sample_percent can be applied to specific tables. In the following example, 50% of the
HR.EMPLOYEES table will be exported:
If you specify a schema, then you must also specify a table. However, you can specify a table without specifying a schema; the current user will be assumed. If no table is specified, then the
sample_percent value applies to the entire export job.
You can use this parameter with the Data Pump Import
PCTSPACE transform, so that the size of storage allocations matches the sampled data subset. (See the Import "TRANSFORM" parameter.)
SAMPLE parameter is not valid for network exports.
In the following example, the value
SAMPLE is applied to the entire export job because no table name is specified.
> expdp hr DIRECTORY=dpump_dir1 DUMPFILE=sample.dmp SAMPLE=70