Default: YES
Purpose
Determines whether Data Pump can use Oracle Real Application Clusters (Oracle RAC) resources and start workers on other Oracle RAC instances.
Syntax and Description
CLUSTER=[YES | NO]
To force Data Pump Export to use only the instance where the job is started and to replicate pre-Oracle Database 11g release 2 (11.2) behavior, specify CLUSTER=NO
.
To specify a specific, existing service and constrain worker processes to run only on instances defined for that service, use the SERVICE_NAME
parameter with the CLUSTER=Y
ES parameter.
Use of the CLUSTER
parameter may affect performance because there is some additional overhead in distributing the export job across Oracle RAC instances. For small jobs, it may be better to specify CLUSTER=NO
to constrain the job to run on the instance where it is started. Jobs whose performance benefits the most from using the CLUSTER
parameter are those involving large amounts of data.
Example
The following is an example of using the CLUSTER
parameter:
> expdp hr DIRECTORY=dpump_dir1 DUMPFILE=hr_clus%U.dmp CLUSTER=NO PARALLEL=3
This example starts a schema-mode export (the default) of the hr
schema. Because CLUSTER=NO
is specified, the job uses only the instance on which it started. (If the CLUSTER
parameter had not been specified at all, then the default value of Y
would have been used and workers would have been started on other instances in the Oracle RAC, if necessary.) The dump files will be written to the location specified for the dpump_dir1
directory object. The job can have up to 3 parallel processes.